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\ 











































































A TREATISE 




ON 

HIGHWAY CONSTRUCTION. 


DESIGNED AS 

A TEXT-BOOK AND WORK OF REFERENCE 


FOR ALL WHO MAY BE ENGAGED IN THE 

LOCATION, CONSTRUCTION, OR MAINTENANCE 

OF 

ROADS, STREETS, AND PAVEMENTS. 


I/* 

AUSTIN T. BYRNE, C.E. 


M 


TRIED REVISED AND ENLARGED EDITION 


FIRST THOUSAND. 




NEW YORK: 

JOHN WILEY & SONS. 

London: CHAPMAN & HALL, Limited. 

1896. 


f . " A\ 
FEi* JIl 1BD6I 

■Et -> S %,J 


. .w- - 

















Copyright, 1892, 

BY 

AUSTIN T. BYRNE. 



Robert Drummond, 
Electrotyper, 

AW and 446 Pearl St., 
New Yoric 









PKEFACE, 


Although volumes have been written on the subject of high¬ 
way construction, still the matter is widely scattered through the 
iges of the standard works on engineering, technical journals 
id periodicals, in pamphlets and reports of city engineers, and is 
lerefore not always easily accessible when wanted. 

The author, having found the need of a comprehensive and 
Tactical work of reference upon the many subjects connected with 
highways, has in the following pages endeavored to collate the 
varied mass of information. In doing so he has derived valuable 
assistance from the works of the authors mentioned below (which 
works may be profitably studied by those desiring further infor¬ 
mation upon the subjects treated of), and takes this method of 
acknowledging his indebtedness and thanks, instead of inclosing 
every extract in quotation-marks. 

AUTHORS AND PUBLICATIONS REFERRED TO. 

Allnutt .—Wood Pavements; Prize Essays on Road-making and Main¬ 
tenance. 

A Move for Better Roads. 

Baker .—Masonry Construction; Cost of Bad Roads, in Report of the 
Illinois Society of Engineers and Surveyors. 

Baumeister .—The Cleaning and Sewerage of Cities. 

Boulnois .—Dirty Dust-bins and Sloppy Streets; The Municipal and 
Sanitary Engineer’s Handbook. 

Burgoyne .—On Rolling New-made Roads. 

Burnell.— Selection, Inspection, and Use of Cement and Mortar (a 
paper read before the Engineers’ Club of St. Louis). 

Brande .—Encyclopaedia of Science, Literature, and Art. 

m 





IV 


PREFACE. 


Callanan . —Roads and Road-making. 

Clark. —Recent Practice in the Construction of Roads and Streets 
(London). 

Cluss. —Mortars and Concretes of Antiquity and Modern Times (a 
paper read before the American Institute of Architects). 

Codrington. —Maintenance of Macadamized Roads. 

Dobson. —Pioneer Engineering. 

Encyclopaedia Britannica. 

Engineering and Building Record. 

Engineering Magazine. 

Engineering News and American Railway Journal. 

Gillespie. —The Principles and Practice of Road-making. 

Gillmore. —Roads, Streets, and Pavements; Limes, Hydraulic Cements, 
and Mortars; Strength of the Building Stones in the United States. 

Good Roads. 

Greene. —The Construction and Care of Streets (a paper read before 
the Commonwealth Club of New York); Asphalt and its Uses (a paper 
read before the American Institute of Mining Engineers); Roads and 
Road-making (in Harper’s Weekly). 

Harper’s Weekly. 

Haapt .— Common Roads, in Reports of the Pennsylvania Board of 
Agriculture; The Best Arrangement of City Streets, in Franklin Institute 
Journal; Importance of Good Wagon-roads, in Engineering Magazine; 
Engineering; Specifications and Contracts. 

Haywood. —Reports Addressed to the Commissioners of Sewers of the 
City of London. 

Henck. —Field-book for Railroad Engineers. 

Herschel. —The Science of Road-making. 

Hughes. —The Roads and Walks of Central Park, New York. 

Hurst .— Architectural Surveyor’s Handbook. 

Jenks .— Road Legislation for the American State. 

Journal of the Association of Engineering Societies. 

Journal of the Franklin Institute. 

Journal of the Society of Arts. 

Knight .— American Mechanical Dictionary. 

Kuichling. —Cement Mortars for Use in Public Works (Report to the 
Executive Board of the City of Rochester, New York). 

Law. —The Art of Constructing Common Roads. 

Lippincott’s Magazine. 

Love .—Pavements and Roads. 

McClanalian. —Roads and Road-drainage, in Report of the Illinois So¬ 
ciety of Engineers and Surveyors. 

Mahan. —Civil Engineering. 



PREFACE. 


V 


Manuel de l’Inggnieur des Ponts et Chauss6es. 

Mathewson. —City Streets: How to Build them and Why (a paper read 
before the Ohio Society of Surveyors and Civil Engineers). 

Molesworth. —Poeketbook of Formulae and Memorandum. 

Morin. —Aide Memoir; Experience sur le Tirage des Voitures. 

Moseley. —Mechanics of Engineering. 

Nelson. —Making and Mending of Country Roads, in Harper’s Weekly. 
Newberry. —The Street Pavements of New York, in School of Mines 
Quarterly. 

North. —Construction and Maintenance of Roads; Highways and Na¬ 
tional Prosperity, in Engineering Magazine. 

Nystrom. —Poeketbook of Mechanics. 

Paget. —Report on the Economy of Road Maintenance and Horse-draft 
through Steam Road-rolling. 

Parnell. —Treatise on Roads. 

Paving and Municipal Engineering. 

Pennell.— What I Know about European Roads, in Harper’s Weekly. 
Pope. —Improvement of City Streets. 

Potter. —The Common Roads of Europe and America, in the Engineer¬ 
ing Magazine; Our Common Roads, in the Century Magazine; The Gospel 
of Good Roads. 

Proceedings of the Association of Municipal and Sanitary Engineers 
and Surveyors. 

Proceedings of the Institution of Civil Engineers. 

Rankine — Civil Engineering. 

Reports of the Engineer Department of the District of Columbia. 
Reports of the Pennsylvania Board of Agriculture. 

Reports of the Tenth and Eleventh United States Census. 

Reports of the United States Geological Survey. 

Reports of Various City Civil Engineers. 

Rhawn. —A Plea for Better Roads. 

Ripley. —Improved Roads (an address before theJSTew Jersey State 
Board of Agriculture). 

School of Mines Quarterly. 

Scribner’s Magazine. 

Searles.— Field Engineering. 

Shaler. —The Common Roads, in Scribner’s Magazine. 

Shunk. —Treatise on Railway Construction and Location for Young 
Engineers. 

Smith. —Parks and Pleasure Grounds. 

Speed. —The Common Roads of Europe, in Lippincott’s Magazine. 

Spon. —Dictionary of Engineering. 

Stone. 





VI 


PREFACE. 


The Century Magazine. 

The Clay Worker. 

The Manufacturer. 

The Sanitarian. 

The Technologist. 

The Transit. 

Torrey .—Pavement Construction and Economies (an address at the 
Street-paving Exposition, Indianapolis). 

Transactions of the American Society of Civil Engineers. 

Transactions of the Canadian Society of Civil Engineers. 

Trautwine .—Engi neer’s Pocketbook. 

United States Consular Reports on the Streets and Highways of For¬ 
eign Countries. 

Vose .—Manual for Railroad Engineers. 

Waddell .—General Specifications for Highway Bridges. 

Wellington .—The Economic Theory of Railway Location. 

Wheeler .—Repair and Maintenance of Roads. 

Wilkins .—Mountain Roads, etc. 

Wright. —Mechanical Dictionary. 







PREFACE TO THE THIRD EDITION. 


The favorable reception of the previous editions and the advance 
made in every branch of highway construction and maintenance 
have induced the author to revise aud enlarge the work, and thus 
keep up with the progressive spirit of the age and render it more 
worthy of approbation. _ 

A large amount of new matter has been added and many im¬ 
portant alterations have been made. Defective illustrations have 
been replaced with new and better ones. 

Among the principal additions to the subject matter in this' 
edition may be mentioned the articles on bitumen, asphaltum, and 
asphalt, the varieties and nomenclature of asphalt, fluxes for 
asphaltum, causes of failure of asphalt pavements, tests of paving- 
brick, blast-furnace slag, chert, Florida clay, artificial stone, sta¬ 
tistics of roads in the United States, etc. 

The selection of tools, machinerv, and other articles of manu- 
facture for reference and illustration has been guided solely by 
their merits and fitness for the intended purpose. 

The writer takes this opportunity to gratefully acknowledge the 
kindness of those who have assisted in furnishing data, etc. 

A. T. B. 


vii. 


New York, February , 1896. 






TABLE OF CONTENTS. 


\ 


CHAPTER I. 

PAVEMENTS. 

PAGE 

Object of pavements—The qualities essential to a good pavement—The 
interests affected in the selection of pavements—Selection of suitable * 
pavements—Cost of wagon transportation—Cost of railroad transpor¬ 
tation—Effect of reducing the cost of wagon transportation—Problem 
involved in the selection of the most suitable pavement—Adaptability 
—Desirability—Economic desirability of pavements—Tractive force 
required on different pavements—Number of horses required to move 
a given load on different pavements—Economy of smoothness—Ser¬ 
viceability-Comparative safety—Observations of Capt. Greene—Ob¬ 
servations of Col. Haywood—Deductions from the observations—Con¬ 
dition of the weather and slipperiness—Cause of the difference in the 
observations of Capt. Greene and Col. Haywood—Slipperiness, cure 
for—Durability—Causes affecting durability—Durability of different 
pavements—Cost of pavements—Cheapest pavement—What a good 
pavement should cost—Economy and public bodies—First cost— 
Relative economies—Maintenance—Prevailing opinion regarding 
pavements—Cleansing—Comparison of pavements with regard to 
facility of cleaning—Annual cost for service—Consequential damages 
—Disadvantages of dirty and noisy pavements—Gross cost—Traffic 
census—Traffic census in the United States—Weights of vehicles— 
Form of traffic census—Tonnage—Guaranteeing pavements—Deferred 
payments—Justification of contracts for maintenance—Destruction of 
pavements—Amount of money wasted in continually opening streets 
—European methods.1 


CHAPTER II. 

MATERIALS EMPLOYED IN THE CONSTRUCTION OF PAVEMENTS. 

Materials employed for paving—Physical and chemical qualities—Break¬ 
ing and crushing tests—Methods of testiug durability—Absorptive 

ix 




X 


TABLE OF CONTENTS. 


PAGE. 

power—Description of materials— Granite—Syenite—Amount and 

value of granite used for street purposes in tlie United States—Price 
of paving-blocks—Various uses of granite—Specific gravity, weight, 
and resistance to crushing of various granites—Manufacture of gianite 

blocks—Sandstone— “Bluestone”—Commercial names of sandstone 

—Analysis of sandstone—Specific gravity, weight, and iesistance to 
crushing—Amount and value of sandstone used for street purposes in 
the United States-Amount and value of bluestone used in 1889- 
Limestone—Uses of limestone—Experience with limestone—Specific 
gravity, weight, and resistance to crushing—Amount and value of 
limestone used in 1889—Trap-rock—Specific gravity, weight, and 
resistance to crushing—Bitumen—Asplialtum Asphalt Oiigin Oc¬ 
currence — Distribution — Nomenclature —Composition—Refined as- 
phaltum—Refining asplialtum—Asphaltic cement—Flax for asphaltum 
—Liquid asphalt—Petroleum residuum—Examination of—Specifica¬ 
tions for— Asphaltic paving materials—Bituminous limestone—Man¬ 
ner of using bituminous limestone—Analysis of European bituminous 
rocks—Bituminous sandstones—Manner of using the sandstone— 
Trinidad Asphaltum—Characteristics of crude Trinidad—Composi¬ 
tion of Trinidad asphaltum—Characteristics of refined Trinidad 
asphaltum—Refining Trinidad asphaltum—Bermuda asphaltum— 
California asphaltum—Asphalt mastic—Analysis and tests of asphal¬ 
tum_Analysis of California asphaltum—Prices of asphaltum—Pro¬ 

duction of in the United States—Imports of in the United States— 
Percentage of the uses of asphaltum—Paving-pitcli—Gas-tar—Brick 

_Clay—Composition of clay—Quality of clay required for paving- 

brick—Manufacture of paving-brick—Analysis of clay—Character¬ 
istics of good paving-brick—Tests of brick—Specific gravity, weight, 
and resistance to crushing—Absorptive power of brick—Wood- 
Quality of wood—Creosoting—Specific gravity, weight, and resistance 
to crushing—Absorptive power of wood—Sand—Use, price, and 
weight of—Gravel—Shingle—Chert ^ 


CHAPTER III. 

STONE PAVEMENTS. 

Early stone pavements—Cobblestone pavement—Belgian block pavement 
—Granite-block pavement—Advantages and defects of granite-block 
pavements—Quality of stone for pavements—Size and shape of the 
blocks—Dressing the blocks—Manner of laying the blocks—Gauging 
the size of the blocks—Foundation for the blocks—Cushion-coat— 
Joint-filling—Bituminous cement— Saudstone-block pavements — 
Limestone-block pavements—Pavements on steep grades—Durability 
of granite blocks—Wear of granite blocks—Cost of maintaining gran- 







TABLE OF CONTENTS. 


XI 


PAGE 

ite-oiock pavements—Method of paying for granite-block pavements 
—Number of blocks to the square yard—Cost of construction of gran¬ 
ite-block pavements—Cost of Belgian block pavements—Cost of sand¬ 
stone-block pavements—Cost of cobblestone pavements—Heads of 
specifications for granite-block pavements ...... 79 

CHAPTER IV. 

WOOD PAVEMENTS. 

"Success of in Europe—Failure of in America—Advantages of—Objections 
to—Wood pavements and death-rate—Systems of wood pavements—• 

Size and form of the blocks—Number of blocks per square yard—Es¬ 
sentials necessary to successful construction—Foundation for wood 
pavements—Chief causes of failure—Quality of the wood—Chemical 
treatment of the wood—Dimensions of the blocks—Expansion of 
wood blocks—Width of joints—Filling for joints—Durability of 
wood pavements—Duration and life of wood pavements in European 
and American cities—Wear of wood pavements—Cost of wood pave¬ 
ments—Cost of maintaining wood pavements—Description of various 
systems of wood paving—Heads of specifications for wood-block pav¬ 
ing—Maintenance of wood pavements by contract—Specifications for 
cedar-block pavements.104 


CHAPTER V. 

ASPHALTUM AND COAL-TAR PAVEMENTS. 

Introduction of asphalt—Difference between European and American 
asphalt—Advantages of asphalt—Defects of asphalt—Durability of 
asphalt—Wear—Cost of construction—Extent of asphalt pavements 
in 1890—Cost of maintenance—Foundation—Asphalt cement pave¬ 
ments— Composition of—Failure of—Trinidad asphalt pavements— 
Composition of, preparation of—Experiments with asphalt pavements 
in various cities—Heads of specifications for standard Trinidad 
asphaltum pavement—Specification for asphaltum pavements on bitu¬ 
minous base—On hydraulic base—On surface of old pavements— 
Maintenance of asphalt pavements by contract—Bermudez asphalt— 
European asphalt pavements—Bituminous-limestone pavements in 
America—Coal-tar pavements—Coal-tar and asphaltum—Vulcanite 
pavement—Advantages and defects of coal-tar or distillate pavements 
— Specifications for coal-tar distillate pavements — Asphalt-block 
pavements—Advantages and defects—Cost of asphalt-block pave¬ 
ments—American bituminous-rock pavements—Specifications for . 135 






xn 


TABLE OF CONTENTS. 


CHAPTER VI. 

BRICK PAVEMENTS. 

PAGE 

Advantages and defects of brick pavements—Durability of—Size and 
shape of the bricks—Quality of the bricks—Foundation for—Manner 
of laying—Cost of brick pavements—Variety of systems—Heads of 
specifications for brick pavement ....... 179 

CHAPTER VII. 

BROKEN-STONE PAVEMENTS. 

Introduction of broken-stone pavements—Methods of Tresaguet, Telford, 
and Macadam—Modern Telford and Macadam pavements—Defects of 
Telford system—Defects of Macadam system—Advantages of broken- 
stone pavements—Defects common to all broken-stone pavements— 
Essentials requisite to successful construction—Erroneous methods of 
construction—Quality of the stone—Size of the stones—Shape of the 
stones—Breaking of the stone—Hand-breaking—Cost of breaking by 
hand—Amount broken by baud—Stone-crushers—Cost of operating 
crushers—Amount of stone broken by crushers—Dimensions, capacity, 
etc., of stone-crushers—Cost of quarrying and crushing stone—Voids 
in broken stone—Weight of broken stone—Area covered by a cubic 
yard of broken stone—Thickness of the broken stone—The New 
Jersey and Bridgeport roads—Number of cubic yards of broken 
stone required per mile—Spreading the stone—Thickness of the 
layers—Binding, necessity of, qualities of—Injurious effects of large 
amounts—Practice of the French engineers—Watering—Compacting 
the broken stone, by traffic, by horse rollers, by steam rollers—Defects 
of traffic consolidation—Advantages of rolling—Defects of horse 
rollers—Introduction of steam rollers—Advantages of steam rolling— 
Pressure exerted by rollers and by loaded vehicles—Defects of wide 
rollers—Objections to picks on steam rollers—Steepest grade on which 
a steam roller can be operated—Cost of maintaining steam rollers— 
Amount of rolling—Manner of applying the roller—Cost of rolling— 

Cost of broken-stone pavements—Difference in cost of broken stone 
pavements in Europe and America—Wear of broken-stone pavements 
—Cost of maintaining broken-stone pavements—Specifications of 
modern broken-stone roads in England—Methods of construction 
adopted in Chicago, in Bridgeport, in St. Louis—Heads of specifica¬ 
tions for broken-stone pavements .... . 195. 





TABLE OF CONTENTS. 


XUI 


-3T 


CHAPTER VIII. 

MISCELLANEOUS PAVEMENTS. 

PAGE 

Gravel, quality of—Preparing and laying the gravel—Repairing gravel 
roads—Cost of construction—Weight of gravel—Bituminous macadam 
—Preparing and laying—Concrete macadam—Stone trackways, 
advantages of—Trackways in Italy—Cost of stone trackways— 
Jasperite—Artificial-granite blocks—Plank roads—Method of construc¬ 
tion—Life and cost of plank roads—Log roads—Charcoal—Iron— 
Blast-furnace slag—Chert—Florida clay—Tar-macadam—Artificial 
stone—Hydraulic cement—clinkers .229 


CHAPTER IX. 

FOUNDATIONS. 

Necessity of foundations—Essentials necessary to the forming of stable 
foundations—Influence of the character of the soil—Defects of sand 
and plank foundations—Blast-furnace slag as a foundation-material— 
Concrete, advantages of—Thickness of the concrete—Quality of the 
concrete—Strength of the concrete—Specific gravity of concrete— 
Proportions—Determination of voids in the broken stone—Voids in 
sand—Quantity of water, some of the usual proportions—Mixing, lay¬ 
ing, and ramming the concrete—Transverse strength of concrete—Com¬ 
pressive strength of concrete—Cost of concrete—Proportions for Port- 
land-cement concrete—Limes, characteristics of—Cements, natural and 
artificial—Tests of cement—Characteristics of Portland cement—Test¬ 
ing cement—Composition of mortar—Quality and quantity of sand— 
Quantity of water—Strength of mortar—Effect of frost on mortar— 
Weight of cement—Specifications for concrete—Specifications for the 
preparation of the roadbed.245 


CHAPTER X. 

RESISTANCE TO TRACTION. 

Conditions causing resistance to traction—Want of uniformity of the 
surface—Resistance of penetration—Rolling, resistance of wheels— 
Experiments of M. Dupuit—Friction—Resistance to traction on differ¬ 
ent road-surfaces—Experiments of MM. Dupuit and Morin—Gravity 
—Tractive power of horses and gradients—Work done by a horse— 
Loss of tractive power on inclines—Effect of inclines on the load a 
horse can draw—Steep grades objectionable—Equivalent length of 
inclined and level roads—Character of vehicles—Width of tires—Size 
of wheels—Effect of wheels.289 





xiv 


TABLE OF CONTENTS. 


CHAPTER XI. 

LOCATION OF COUNTRY ROADS. 

PAG Is 

Considerations governing location—Principles governing location— Econ¬ 
omy of motive power—Selection of best route—Reconnaissance, object 
of—Points to be attended to in making reconnaissance—Configuration 
of the country—Ridges and passes—Water-courses and valleys— 
Streams give the direction of the high ground — Preliminary 
survey—Data to be obtained on preliminary surveys—Topogra¬ 
phy—Map—Memoir—Levels—Cross-levels—Profile — Bridge sites— 
Principles to be observed in making final selection—Examples of 
cases to be treated—Intermediate towns—Mountain roads—Method 
of surveying mountain roads—Loss of height—Water on mountain 
roads—Halting places—Alignment—Curves, kind of—Reduction of 
grade on curves—Increasing wheelway on curves—Excessive crook¬ 
edness to be avoided—Curving roads, advantages of—Zigzags, objec¬ 
tions to—Final location—Construction profile—Gradient, definition 
of—Determination of gradients—Angle of repose, to ascertain—Trac¬ 
tive power required in descending inclines—Men and animals ascend¬ 
ing steep slopes—Maximum grade and traffic—Maximum grade to be 
adopted—Maximum suitable for various pavements—Maximum 
adopted by Telford—Maximum adopted by the French engineers— 
Smooth and rough surfaced inclines—Determination of maximum 
grade—Grade of mountain roads—Minimum grade—Minimum grade 
adopted by the French engineers—Undulating grades—Level stretches, 
objections to—Vertical curves, application of—Different methods of 
designating the same grades.309 


CHAPTER XII. 

WIDTH AND TRANSVERSE CONTOUR. 

Width of roadways—Minimum width—Advantage of wide roads—Width 
of land appropriated for road purposes in various localities—Width of 
mountain roads—Number of acres required per mile for different 
widths—Transverse contour, object of—Amount of rise required for 
different pavements—Form of transverse contour—Form for streets— 
Form for country roads—Excessive rise, evils of—Straight sides objec¬ 
tionable—Concave form not desirable—Contour on hillside roads . 332 



TABLE OF CONTENTS. 


XY 


CHAPTER XIII. 

EARTH-WORK. page 

Earth-work, definition of—Equalizing eartli-work—Transverse balancing 
—Borrow-pits—Spoil-banks—Staking out of borrow-pits—Shrinkage 
of earth—Increase of rock—Settlement of embankments—Failure of 
earth-work—Stability of earth-work—Angle of repose of earths— 
Angle of slopes—Effect of moisture on earth—Angle of slopes in rock 
excavation—Form of side slopes—Protection of side slopes—Slips— 
Catch-water ditches—Drainage of side slopes—Embankments, best 
materials for—Manner of forming embankments—Slopes of embank¬ 
ments—Drainage of embankments—Embankments over plains—Em¬ 
bankments across marshes—Description of an embankment formed 
by Mr. G. Waite, C. E.—Embankments across bogs—Embankments 
on hillsides—Roadways on rock-slopes—Rock excavation—Blasting 
—Quantity of rock loosened—Line of least resistance—Quaulity of 
powder required—Cost of excavating rock—Haul—Cost of earth-work 
—Loosening earth—Transport of earth—Limits to which shovels, 
wheelbarrows, carts, scrapers, and dump-wagons may be employed— 
Loosening and transporting by machinery—Calculating amount of 
earth-work—Calculation of half-widths anil areas—Examples of cross- 
sections of earth-work—Calculation of sectional areas—Formulae for 
the calculation of areas—Table of cubic contents .... 337 


CHAPTER XIY. 

DRAINAGE AND CULVERTS. 

Drainage, object and necessity of—Methods employed for securing drain- 
age—Division of natural soils—Mitre-drains—Tile-drains—Silt-basins 
—Protection of drain-outlets—Cost of drains—Fall of drains—Side 
ditches—Springs, treatment of—Drainage of the surface—Protection 
of gutters—Water-breaks objectionable—Catch-water ditches—Cul- 
ver t s _Area of water-way—Rainfall—Determination of area of water¬ 

way Catch-pools—Materials for culverts—Cement and earthenware 

pipes, dimensions and cost of—Iron pipe-culverts, dimensions and cost 
0 f_Box-culverts—Arch-culverts—Thickness of arch—Thickness of 
abutments—Dimensions and cost of drain-tile—Discharging capacity 
of circular pipes 




xvi 


TABLE OF CONTENTS. 


CHAPTER XV. 

BRIDGES, RETAINING-WALLS, PROTECTION WORKS, TUNNELS; 

FENCING. 

Bridges, importance of—Care in their construction—The loads for which 
bridges should be proportioned—Materials for bridges—Wood—Types 
of timber bridges—Diagrams and dimensions of timber bridges—Sub¬ 
structure of bridges—Retaining-walls—Proportions of retaining-walls 
—Form of retaining-walls—Dry stone retaining-walls—Foundation of 
retaining-walls—How retaining-walls fail—Coping for retaining-walls 
—Weep-holes—Formulae for calculating the thickness of retaining- 
walls—Surcharged walls—Least thickness of retaining-walls—Where 
retaining-walls should be built — Protection of roads — Parapets, 
dimensions of—Earth mounds—Wooden railings afford no protection 
—Guard - stones—Roads along the seashore, margin of rivers and 
lakes—Bulkheads and masonry walls—Tunnels—Fences—Cost of 
fencing.396 


CHAPTER XYI. 

CITY STREETS. 

Laying out of streets—Best arrangement of streets—Width of streets— 
Street grades—Grade at street-intersections—Accommodation summits 
—Transverse grade—Transverse contour—Sub-foundation drainage 
of streets—Surface drainage of streets—Gutters—Catch-basins—Street 
lines and monuments—Street profiles—Increasing the width of the 
carriageway at street corners.414 

CHAPTER XVII. 

FOOTPATHS, CURBS, GUTTERS. 

Footpaths, definition of—Qualities required—Width—Cross-slope—Foun¬ 
dation—Surface requirements—Materials employed for footpaths— 
Stone, manner of dressing—Specifications for flagstones—Wood— 
Asphalt—Proportions and materials employed in Paris—Number of 
square yards that a ton of prepared asphalt will lay—Life of asphalt 
footways—Specifications for asphalt footway pavements—Brick—Spec¬ 
ifications for brick walls—Artificial stone, varieties of—Formation of 
artificial stone—Wear of artificial stone—Specifications for concrete 
footwalks—Specifications for artificial-stone footwalks—Tar concrete 
—Specifications for tar-concrete footpaths—Gravel, manner of con¬ 
structing—The Central Park walks—Drainage of gravel walks— 






TABLE OF CONTENTS. 


XVII 


PAGH 

General directions for the construction of gravel walks—Curbstones— 
Specifications for granite curb—Specifications for bluestone curb— 
Specifications for setting curb—Specifications for artificial-stone curb 
and gutter—Specifications for dressing old curb—Specifications for 
resetting curb—Hollow curbs—Gutters—Specifications for cobble gut¬ 
ters—Specifications for brick gutters —Specifications for gutter-stones 
—Crossing or bridge-stones—Specifications for bridge-stones—Speci¬ 
fications for relaying bridge-stones—Prices.438 

CHAPTER XVIII. 

RECONSTRUCTION AND IMPROVEMENT OF COUNTRY ROADS. 

Rectification of alignment and grades—Drainage—Improvement of the 
surface—Improving clay roads—Improving sand roads—Scraping or 
road machines, manner of using—Cost of constructing earth roads— 

Cost of maintaining earth roads—Value of improvements, how to 
ascertain—Data required—Defects of existing roads—Profit of elimi¬ 
nating unnecessary grades—Profit of eliminating unnecessary length— 
Profit of improving the surface—Annual loss occasioned by bad roads 485 

CHAPTER XIX. 

MAINTENANCE.—REPAIRING; CLEANSING; AND WATERING 

Maintenance, definition of—Necessity of—What good maintenance com¬ 
prises—System of maintenance—Maintenance of country roads— 
Directions for maintaining macadamized highways—Cost of mainten¬ 
ance—Repair—Organization of road force—Instructions to roadmen 
—System of highway maintenance adopted in France—Street cleans¬ 
ing—Intervals at which it is performed—Objections to dusty streets— 
Dirt-producing causes—Composition of street dust—Amount of refuse 
collected from city streets—Amount of dirt produced by different 
pavements—Methods employed for cleansing—Systems of executing 
the work—Cost of cleansing—Methods of cleansing employed in 
Berlin, Paris, London, Baltimore, Boston, and other American cities 
—Street orderly system—Cost of street sweeping—Amount of surface 
swept by one man—Amount of surface swept by a machine broom— 

Cost of operating mechanical sweepers—Brooms—Carts and wagons— 
Disposal of street dirt—Removal of snow—Methods employed— 
System adopted in Milan—Disposal of snow—Weight of snow— 
Street washing—Street sprinkling—Systems employed—Quantity of 
water required—Cost of sprinkling—Sea-water for street sprinkling . 493 



XVUl 


TABLE OF CONTENTS. 




CHAPTER XX. 

TREES. pags 

Opinions regarding the planting of trees on roads and streets—Trees on 
the French and Belgian roads—Financial value of trees—Fruit-trees 
in Saxony—Selection of trees—Qualities necessary to good road-trees 
—Distance apart to plant trees—Trees at street-intersections—Protec¬ 
tion of trees.545 


CHAPTER XXL 
STAKING OUT THE WORK. 

Object of—Distance apart of stakes—Straight lines and curves—Side 
slopes—Setting out culverts—Length of culverts—Setting out bridges 
—Drains, setting out—Setting out vertical curves—Staking out trans¬ 
verse contour of street pavements—Setting stakes for curb—Setting 
stakes for any structure—Fixing lines upon water—Bench marks . 550 

CHAPTER XXII. 

SPECIFICATIONS AND CONTRACTS. 

Specifications, contents of—Tests of materials—Contracts—General speci¬ 
fications for clearing—Close-cutting—Grubbing—Grading—Forma¬ 
tion of embankments—Earth-work measurement and classification— 
Drains—Catch-water ditches—Off-take ditches—Rip-rap—Retaining, 
breast, slope, and parapet walls—Culverts—Masonry, classification 
of—Arch-culvert masonry—Centring—Laying masonry in freez¬ 
ing weather—Pointing—Grouting—Brick masonry—Dry walls—Dry 
box-culverts—Pipe-culverts—Cement—Cement tests—Sand—Mortar 
—Concrete—Foundation excavation—Artificial foundations—Timber 
—Piles—Cofferdams—Wrought-irou—Cast-iron—General stipulations 
applicable to all contracts—Interpretation of specifications—Omissions 
in specifications—Engineer defined—Contractor defined—Notice to 
contractor, how served—Preservation of engineer’s marks and stakes 
—Dismissal of incompetent persons—Spirituous liquors—Quality of 
materials—Samples—Deviations from plans and specifications—Right 
reserved to alter details—Inspectors—Defective work—Measurement 
of work — Excavation — Overhaul — Masonry — Timber—Piles—Cul¬ 
verts and drain-pipe—Stone, brick, and pole drains—Concrete—Curb¬ 
ing—Gutters—Crossing or bridge-stones—Catch-basins—Bridges— 
Pavements—Partial payments—Commencement of work—Time of 
completion—Progress of work—Forfeiture of contract—Damages for 
non-completion—Evideuce of payment of claims—Protection of per¬ 
sons and property—Bond for faithful performance of work—Power 
to suspend work—Loss and damage—Miscellaneous work—Cleaning 







TABLE OF CONTENTS. 


XIX 


PAGE 

up—Personal attention of contractor—Contract not to be assigned— 
Payment of workmen—Prices—Payments, when made—Heads of 
specifications for a highway—Specifications for a bulkhead—Heads 
of specifications for grading, macadamizing, curbing, and flagging— 
Specifications for the supply of broken stone—Indemnification for 
patent claims—Indemnity bond—Right to construct sewers—Old ma¬ 
terials, disposal of—Security retained for repairs—Alteration of man¬ 
hole covers stopcock boxes, etc.—Heads of specifications for repav¬ 
ing—Specifications for street cleansing—Instructions to bidders— 
Form of proposal—Form of agreement—Form of bond . . . 557 

CHAPTER XXIII. 

IMPLEMENTS AND PRICES. 

Description and prices—Tools for clearing—Tools for grading—Mechanical 
graders—Tools for draining—Tools for rock excavation—Hand-drills 
—Steam-drills—Tools for macadamizing—Stone-crushers—Sprinkling- 
carts—Horse rollers—Steam rollers—Tools employed in the main¬ 
tenance of macadam roads—Tools employed for block pavements— 
Concrete-mixing machines—Tools employed for asphalt pavements— 
Tools used for cleansing pavements—Mechanical sweepers—Street 
patrol hand-cart—Sprinkling-carts—Snow-shovels and ploughs—Tools 
employed for artificial stone pavements—Catch-basins—Sewer-inlets 
and gutter-crossings.604 


CHAPTER XXIV. 

MISCELLANEOUS NOTES. 

Comparison of European and American Methods and Prices—Statistics of 
Roads in the United States—Average Weight of Load for Horses— 
Average Cost of Haulage per Ton per Mile—Average Length of Haul 
from Farms to Market—Average Total Cost per Ton for the Whole 
Length of Haul—Pavements and Horseshoes—Annual Cost of Struc¬ 
tures—Interest and Sinking-fund Tables.680 

APPENDIX I.—Naming and Numbering Country Roads and Houses . 692 
APPENDIX II.—Methods of Assessing the Cost of Street Paving . . 702 


I 



LIST OF TABLES. 


NUMBER PAGE 

1. Cost of wagon transportation on different road-surfaces. 3 

2. Tractive force required upon level roads of different materials. 6 

3. Comparison of gross cost of pavements. 18 

4. Comparative rank of pavements. 21 

5. Absorptive power of stone. 26 

C. Specific gravity, weight, and resistance to crushing of granites. 28 

7. Production and value of granite in the United States in 1889 for street 

uses. 29 

8. Analyses of sandstones . 32 

9. Specific gravity, weight, and resistance to crushing of sandstone_ 33 

10. Production and value of sandstone in the United States in 1889 for 

street uses. 34 

11. Production and value of bluestone used for street purposes in the 

United States in 1889. 34 

12. Specific gravity, weight, and resistance to crushing of limestones.... 35 

13. Production and value of limestone used for street purposes in the 

United States in 1889. 36 

14. Specific gravity, weight, and resistance to crushing of trap rocks._... 37 

14a. Composition of asphaltum. 42 

15. Analyses of European bituminous rocks. 50 

15a. Composition of Trinidad asphaltum. 52 

17. Prices of asphaltum in 1889.. 61 

18. Production of bituminous rock in the United States in 1889. 62 

19. Imports of asphaltum in 1890... 62 

20. Analyses of clay... 66 

21. Tests of paving-brick. 68-69 

22. Specific gravity, weight, and resistance to crushing of wood. 73 

23. Absorptive power of wood. 74 

24. Specific gravity, weight, and resistance to crushing of various sub¬ 

stances. 77 

25. Wear and duration of granite pavements in London. 94 

26. Number of granite blocks to the square yard. 97 

27. Cost of granite block in various cities in the United States in 1890.... 98 

28. Extent and cost of Belgian block in the United States in 1890... 99 

xxi 





























XXII 


LIST OF TABLES. 


NUMBER PAGE 

29. Extent and cost of sandstone block in the United States in 1890. 99 

30. Extent and cost of cobblestone in the United States in 1890. 100 

31. Duration and cost of wood pavements in London. 115 

32. Wear of wood pavements. 118 

33. Extent and cost of wood pavements in various localities. 119 

34. First cost and cost of maintaining wood pavements iu London. 120 

35. Extent and cost of asphalt pavements in various cities. 142 

36. Cost of asplialt-block pavements iu various cities. „,. 175 

37. Cost of brick pavements. 184 

38. Coefficients of quality of stones. . . 203 

39. Cost of quarrying and crushing stone... 207 

40. Number of cubic yards of broken stone required per mile of road.... 210 

41. Cost of broken-stone roads.. . 217 

42. Cost of broken-stone pavements in various cities.218 

43. Cost of gravel pavements. 231 

44. Amount of water absorbed by Portland cement. 262 

45. Adhesive strength of mortars. 271 

46. Shearing strength of mortars.. .. 272 

47. Tensile strength of mortars. 273 

48. Effect of size of grain of sand on teusile strength of mortar.276 

49. Character of sieves for sifting sand. 276 

50. Resistance to traction on different road-surfaces.295 

51. Tractive force required on pavements in Paris and London.298 

52. Resistance of gravity on different, grades. 298 

53. Tractive power of horses at different velocities. 301 

54. Duration of a horse's daily labor aud maximum velocity unloaded... 301 

55. Increase iu tractive power. 301 

56. Maximum amount of labor a horse is capable of performing at differ¬ 

ent velocities. 302 

57. Gross load which a horse can draw on different grades. 302 

58. Effect of grades upon the loads a horse can draw on different pave¬ 

ments. 303 

59. Force required to draw loaded vehicles on inclines and equivalent 

level roads. 304 

60. Best width of wheel-tires. 306 

61. Coefficient of resistance for different pavements..328 

62. Methods of designating grades. 330 

63. Number of acres required per mile for different widths of roadways. 333 

64. Amount of transverse rise for different pavements. 334 

65. Natural slopes of earths . 341 

66. Lengths and angles of slopes. 341 

67. Amount of powder required. 358 

68 . Capacity of drill-holes... . 353 

69. Coefficient for different earth-slopes .. 367 

70. Earth-work table. 359 










































LIST OF TABLES. 


xxiii 


NUMBER 


PAGE 


71. Cost and weight of vitrified culvert-pipe. 

72. Cost and weight of Portland-ceinent pipe. 

78, Dimensions, weight, and prices of iron pipe. 

74. Dimensions of box-culverts. ... 

75. Thickness of arches.. 

76. Thickness of abutments. 

77. Dimensions, weight, and prices of drain-tile. 

78. Discharging capacity of circular-pipes. 

79. Span and dimensions of bridges. . 

80. “ “ “ “ “ ... 

81. Coefficients for thickness of retaining-walls.-. . 

82. Width, maximum grade, and average width of sidewalks in several 

cities..... 

88 . Street statistics of various cities. 


387 

387 

388 
390 
392 

394 

395 
395 

400 

401 
408 

422 

437 


84. Number of square yards that one ton of prepared rock asphalt will 

lay. -. 

85. Composition of dirt from paved streets. 

86 . Amount of refuse collected from city streets. 

87. Average cost per head of population for street maintenance in various 

cities. . .. 

88 . Wages in European countries... 

89. The amount of one dollar at compound interest for a term of years.. 

90. The annual sinking fund that with compound interest will amount to 

one dollar at the end of a term of years... 


441 

524 

525 


528 

680 

686 

68S 


























LIST OF ILLUSTRATIONS. 


FIGURE PAGE 

1. Roman pavements. 79 

2. Cobblestone pavements. 79 

3. Belgian block pavements. 79 

4. Early granite-block pavements. 79 

5-7. Improved granite-block pavement. 83 

7 a, 7 b. Street-intersection paved with granite blocks...86, 87 

8 . Cobblestones on steep grades. 92 

9, 10. Granite block on steep grades . 92 

12. Section of wood pavement. 108 

13. Plan of wood pavement at street-intersections. 108 

13n. Pavement of round blocks. 109 

14. 15, 15a-15b. Sections of asphalt pavements. 137 

16, 17. Hale brick pavement. 180 

18. Section of brick pavement on concrete. . 180 

19. Brick pavement at street-intersections .. 180 

19 a. Hayden paving-block.. 185 

20. Broken-stone pavements in France previous to 1775. 196 

21. Tresaguet’s system. 196 

22. Telford’s system. 196 

23. Macadam’s system. 196 

24. Shape of stone for broken-stone pavements. 204 

25-28. Type sections of broken-stone pavements. 226 

29-32. Stone trackways . 234, 235 

33. Form of briquette for testing tensile strength of cement. 267 

34. Clamps for holding briquette. 267 

35. Cement testing-machine. 267 

36. Diagram, resolution of forces in overcoming obstacles on roads.289 

37-39. Diagrams illustrating resistance of penetration.291, 292 

40. Resolution of the force of gravity on inclined planes.299 

41. Mechanical advantage of wheels. 308 

42. Contour map. 313 

43. Map of preliminary surveys. 314 

44. Preliminary profile. 315 

45. Intermediate towns.319 


xxv 












































XXvi LIST OF ILLUSTRATIONS. 


FIGURE PAGE. 

40. Simple curve. 322 

47. Compound curve.322 

48. Reverse curve. 322 

49. Double reverse curve. 322 

50. Construction profile. 325 

51-58. Application of vertical curves . 331 

54. Transverse contour of streets. 335 

55. Transverse contour for country roads.335 

56. Hillside road showing stepping of slopes and retain in g-w alls.344 

57. Formation of embankments by end dumping. 346 

58. “ “ “ “ layers .. 347 

59. Usual method of forming embankments.348 

60. Embankments over plains. 349 

61. 62. Embankments on hillsides, manner of stepping the slope.353 

63-65. Embankments of rock slopes.354, 355, 356 

66 -68. Formation of a road in the face of a cliff. 356 

69. Profile of cut and fill illustrating calculation of overhaul. 362 

70-76. Examples of earth-work cross-sections.365 

77. Example of profile and cross-sections of earth work. 368 

78. Cross-section of blind drain. 374 

79. “ “ pole drain. 374 

80. “ “ stone drain.. 374 

81. “ “ tile drain. 374 

82. Protection of drain-outlet. 374 

83. 84. Silt-basins. 374 

85-89. Examples of the drainage of country highways. 376 

90. Section of country highway. 379 

91. Drainage of road in embankment. 379 

92. “ “ suburban streets. 379 

93-96. Head-walls for pipe-culverts.. .... 384 

96a. Wing abutment for single pipe-culvert... 385 

966. Head-wall for double pipe-culvert.,.385 

96c. Head-wall for triple pipe culvert.386 

9 6d. Section of pipe-culvert. 386 

97-101. Examples of box-culverts.389 

102-108. Examples of arch-culverts . 391, 393 

109-124. Types of timber bridges. 398 

125-132. Simple timber bridge .400, 401, 402 

132a. Iron swing-bridge. 403 

1326, 132c. Types of iron bridges. 404 

133-136. Examples of retaining-walls. 405 

137-139. “ “ road construction along the seashore or margin of 

rivers. ... . ..410,411 

140. Examples of mound and ditch fence...412 

141, 142. Arrangement of city streets.416, 417, 419 

143, 144 “ “ street-intersections.423-424 

145. Crowns in street gutters. 425 


















































LIST OF ILLUSTRATIONS. XXVU 


KIGUilE page 

14(5-148. Arrangement of streets with opposite sides at different levels_ 426 

149. Sub-foundation drainage of streets. 427 

150-153. Examples of catch-basins.429,430 

153^. Examples of sewer inlet. 431 

154, 155. Surface-drainage at street-intersection.432 

156. Objectionable form of water-way at street crossings.432 

157. Street monument.433 

158,159. Example of widening carriageway at street-intersections. 435 

160. Improper method of dressing flag-and bridge-stones.440 

161. Drainage of park walks.465 

162-166. Fire-clay curb. .. 474 

167. Iron curb.474 

168. Granite curb, Washington, D. C.476 

169. Bluestone curb.. 476 

170. 171. Hollow curb.478 

172. Arrangement of gutter-stones. 479 

173-176. Examples of crossings and gutters.482, 483 

177. Tree-protection. 549 

178. Setting slope stakes. 551 

179. “ out culverts on horizontal ground..... 552 

180. 181 Setting out culverts on sloping ground. 552. 

182. Setting out vertical curves. 554 

183. “ stakes for street contours. 555 

184. “ “ “ curb. 555 

185. “ “ “ any structure...... . .556 

186. Busli-hooks. 604 

187. Axe mattock . 604 

188. Pick mattock. 604 

189. Grading pick. 605 

190. Clay-pick. 607 

191. Shovels. 605 

192. Grading-plougli. 606 

193. Hard pan-plough. 606 

194. 195. Drag-scraper. 607 

196. Pole-scraper. 608 

197-199. Wheeled scraper.* 609 

200-202. Wheelbarrows. 610 

203. Earth-cart. 611 

204, 205. Dump-cars.612 

206,207. Dump-wagon. 615 

208-210. Mechanical graders or road machines.616, 617 

211, 212. New Era grader.618 

■213. Surface-grader. 620 

214. Road-leveller. 620 

215. Draining-tools. 621 

216. Hand-drilling tools. 623 

217. Steam-drill.625 



















































XXV111 


LIST OF ILLUSTRATIONS. 


FIGURE PAGE 

218. Portable boiler. 627 

219. Straight-edge. 628 

220. Roadbed-roller. 629 

221. Sprinkling-cart. 629 

222-283. Stone-crushers. 684-639 

234. Stone-screen. 640 

235, 236. Engines and boilers.641, 642 

237-241. Stone-crushing plants.643-645 

242. Stone-distributing cart. 646 

243-246. Horse-rollers.646-648 

247-251. Steam-rollers...650-652 

252-254. Paving-hammers. 653 

255-259. Paving-rammers. 654 

260. Asphalt rammers. 654 

261. Asphalt smoothing-iron. 654 

262. Fire-pot roller. 655 

263. Portable tire box. 655 

264,265. Steam-rollers for asphalt. 656 

266. Asphalt-mixing machine. 657 

267. Surface-heater for asphalt.658 

268-269. Concrete-mixing machines. 659-660 

270. Sand dryer.661 

271. Portable heater for asphalt. 661 

272-276. Sweeping machines .662-664 

277. Scraping-machine. 665 

278-280 Patrol-cart. 666-667 

281. Hand-scoop. 667 

282. Hand sweeper. 668 

283. Dump-cart. 668 

284-286. Combined sweeping and collecting-machines.669-671 

287, 288. Street sprinklers. 672-673 

289, 290. Snow-ploughs. 673 

291-297. Tools for artificial stone pavements. 674r 

298. Iron catch-basin . 675 

299-300. Gutter-gratings. 676 

301. Sewer inlet-trap. 977 

302, 303. Inlet for broken-stone roads. 675 

304, 305. Gutter crossings .... .. 678 

306. Gutter boxes. 679 










































INTRODUCTION. 


HISTORICAL SKETCH. 

Roads are pathways formed through a country to facilitate the 
movement of persons and exchange of commodities. They are of 
various kinds, according to the state of civilization and wealth of 
the country traversed; thus, they range from rude paths, passable 
only by pedestrians, to the comparatively perfect modern road, 
passable alike by persons and vehicles. 

The motive for the formation of roads is found (1) in the in¬ 
quisitive spirit of man, and his desire for intercourse with his fel¬ 
lows; (2) in the necessity of obtaining provisions for his sustenance 
in times of scarcity; and (3) in the desire to gratify his fancies 
with the products of other localities. 

With the progress of civilization and the congregation of men 
in cities and towns their wants multiply, and the products of the 
earth have to be collected and transported to supply them. Tin 45 
collecting, transporting, and exchanging of products is trade or 
commerce, and its importance and expansion are directly propor¬ 
tional to the facilities afforded. 

Countries inhabited by the least civilized people whose wants 
are supplied by nature in the immediate vicinity of their dwellings 
are almost destitute of roads; hence it has come to be said that 
roads are the physical symbol by which to measure the progress of 
any age or people. “ If the community is stagnant, the condition 
of the roads will indicate the fact; if they have no roads, they are 
savages.” 

Although roads are the offspring of civilization, they have be- 

xxix 



XXX 


HIGHWAY CONSTRUCTION. 


come the chief factors, if not indeed the means, for its advancement. 
Without them the invention of printing and other arts so beneficial 
to the welfare of men would separately be ineffectual, or productive 
of advantages of a very limited extent. Without roads, the inter¬ 
change of advantages, moral, intellectual, and physical, which now 
takes place in all highly civilized countries between the rural and 
urban population, could not be maintained; without them, indeed, 
large towns or cities could not continue to exist. The supply of 
the population collected in such places, with the various products 
of agriculture necessary to their physical existence, could not be 
sustained. Nor, on the other hand, would the rural population 
affording that supply be benefited by a return in exchange of the 
refinements of the town, and the various articles of luxury and 
necessity obtained by commerce from every part of the globe. 

It is frequently asserted that, since the introduction and de¬ 
velopment of railroads, the latter have assumed to a greater and 
greater degree the functions of the common road, and that high¬ 
ways are no longer an indication of progress. This is true to only 
a limited extent. Railroads have changed the character of the 
traffic on the common roads, and personal travel for business 
or pleasure is no longer dependent upon the condition of the high¬ 
ways; but commercial intercourse as represented in the exchange 
of products is as much dependent upon the condition of the public 
road to-day as it ever was, for the reason that it is impossible to 
construct a railroad to the door of each producer and consumer. 
Hence railroads never can supersede the common road, and every 
ton of freight carried by them must be conveyed over a highway 
at either or both terminals, and the cost of this highway transpor¬ 
tation has a marked influence not alone upon the price paid by the 
consumer, but also on the profit realized by the producer. 

If railroads may be compared to the arteries of a living body, 
then the common roads are the veins, and each is equally neces¬ 
sary in quickening and communicating life to the parts to which 
they lead. Rut the true relation between railroads and wagon-roads 
frequently seems to be lost sight of; the functions of each are quite 
different and in no sense rivals. The highway serves the very 
important purpose of effecting local intercourse and of connect¬ 
ing the local freight and passenger traffic with the railroad service. 
Roads running parallel to the railroad and connecting towns al- 




HISTORICAL SKETCH. 


XXXI 


ready joined by the railroad are of but little importance, It is the 
roads running at an angle with the railroad and connecting it with 
the country to the right and left, thus acting as feeders, that re¬ 
quire attention in modern times. In Baden, Germany, this rela¬ 
tion of the roads to the railroads was early recognized by striking 
from the list of state roads all those that ran parallel to the rail¬ 
road or had lost their importance by its construction, in order to 
save funds for the support of the others; while most of those run¬ 
ning across the railroad, if they crossed at a station so that they 
served as feeders, were raised to the grade of state roads. 

The importance of roads to the welfare of nations was not un¬ 
known to the ancients. The senate of Athens, the governments 
of Lacedaemon, Thebes and other states of Greece bestowed much 
care upon them. The Carthaginians were systematic and scientific 
road-makers; they built up and consolidated an empire so promi¬ 
nent in military and naval achievements and in the arts and 
industries of civilized life that for four hundred years it was 
able to hold its own against the preponderance of Greece and 
Rome. 

In Peru the Incas built great roads, the remains of wdiicli attest 
their magnificence. Humboldt in his “ Aspects of Nature ” speaks 
of the mountain road from Quito to Cuzco as “ a marvellous work, 
not inferior to the most imposing Roman roadways.” It was from 
1500 to 2000 miles in length, and most of it was at an elevation of 
over 12,000 feet above the level of the sea; it was 20 feet wide and 
paved with stones 10 feet square, and had a running stream and a 
row of shade-trees on each side. Prescott in his “ History of 
Peru,” in speaking of this road, says that “it was conducted over 
sierras covered with snow; galleries were cut through the living 
rock; rivers were crossed by means of bridges swung suspended in 
the air; precipices were scaled by stairways hewn out of the native 
bed, and ravines of hideous depth were filled up with solid ma¬ 
sonry.” 

As to when paved roads were first introduced little is known, 
but Strabo informs us that the city of Babylon was paved at a 
very early date. The date assigned (2000 b.c.) is perhaps fabulous, 
though it was quite within the capacity of the builders of the city 
walls, palaces, and bridges across the Euphrates to pave the city 
in good style. 




XXX11 


HIGHWAY CONSTRUCTION - . 


/ 


The highway leading from Babylon to Memphis was paved at 
an early date, and along it arose the cities of Nineveh, Palmyra, 
Damascus, Tyre, Antioch, and other great commercial cities. 

The Romans learned the art of making paved roads from the 
Carthaginians, and the highways constructed by them are great 
monuments in this department of art. 

The first Roman road was constructed under the direction of 
the censor Appius Claudius (312 b.c.). This road, named after him 
the Appian Way, was frequently, on account of its excellence, called 
the “ queen of roads." Under Augustus and Julius Caesar the 
Roman capital was made to communicate with all the chief towns 
by paved roadways, and during the last African war a road of this 
kind was constructed from Spain through Gaul to the Alps. 
Later these great lines of communication were extended through 
Savoy, Dauphine, and Provence; through Germany, every part of 
Spain, through Gaul, and even to Constantinople; through Hungary, 
Macedonia, and to the mouths of the Danube. Neither did the in¬ 
terposition of seas obstruct the labor or daunt the enterprise of this 
great people. The lines of communication thus constructed to the 
shores of the continent of Europe were continued at corresponding 
points of the neighboring islands and continents. Sicily, Corsica, 
Sardinia, England, Africa,'and Asia were accordingly penetrated 
and intersected by roads, forming the continuation of the great 
European lines. These gigantic works were the most solid struc¬ 
tures of their kind which have been formed in any age, and many 
of them still remain, often forming the foundation of modern roads 
and in some instances constituting the road-surface now used. 
From these remains and the accounts of ancient writers we are en¬ 
abled to follow the methods employed in their construction. The 
engineering appears to have been very simple. A prominent land¬ 
mark was selected in the direction desired, and the road located on 
an absolute straight line without reference to intervening obstacles. 
The roads were divided into military and local ways. The first 
were built to facilitate the movement of troops and to connect the 
capital with the principal cities and strategic points. They were 
constructed and kept in repair by the imperial government. The 
second were the routes of commerce and connected towns and trade 
centres, and were constructed to facilitate the relations and inter¬ 
course of traffic; they were built and maintained by the municipal 




HISTORICAL SKETCH. 


XXX111 


governments. The width of the roads varied from 8 to 20 feet, 
and the method of construction was as follows: A trench was ex¬ 
cavated the entire length and width of the roadway; in this trench 
the road materials were placed, arranged in four layers having a total 
thickness of about 3 feet: (1) the statumen, consisting of two 
courses of large flat stones laid in lime-mortar; (2) the rudus , 
composed of broken stones mixed with one third their quantity of 
lime and well consolidated by ramming; (3) the nucleus , a 
mixture of broken brick, potsherds, tiles, gravel, and lime; (4) 
the summa crusta, a pavement of irregularly-shaped stones 
about six inches thick, closely jointed and fitted with the 
utmost nicety. These roads bore uninjured the weight of 
columns, obelisks, and other immense blocks of stone weighing 
hundreds of tons; notwithstanding this the utmost weight which 
each class of vehicle was permitted to carry was regulated by law, 
and those laws were strictly enforced. Although these roads were 
eminently durable, they were deficient in the other qualities re¬ 
quisite for a good road, and Horace states that they were “ less 
fatiguing to people who travel slowly/' 

In the breaking-up of society which followed the decline of the 
Roman Empire, the roads fell out of repair and finally into ruin. 
During the Dark Ages they were regarded with terror as aids to 
plunder, and such intercouse as was maintained took place almost 
exclusively by rude paths capable of being passed on foot, or at best 
by horses. With the reconstruction of society in Europe the roads 
gradually became practicable for pack-animals and the rude vehicles 
of the time; but no serious attempt was made to restore or replace 
the public highways until the middle of the eighteenth century. 
About this time the revival of road construction was almost simul¬ 
taneous in England and France, and shortly afterwards the other 
chief countries of Europe took up the matter. 

Regarding the condition of the English highways a hundred 
and fifty years ago, Lord Macaulay tells us that it was no uncom¬ 
mon thing for the fruits of the earth to rot in one place when a score 
of miles away the people were suffering from a scarcity of the very 
food which was spoiling and almost within their reach. The roads 
were so wretched that the food could not be transported. At this 
time each parish was obliged to build and maintain the roads 
within its confines, and it not infrequently happened that a poor 



xxxiv 


HIGHWAY CONSTRUCTION - . 


i 




and impoverished agricultural community was expected to maintain 
a highway between two rich and prosperous towns. 

Mr. Arthur Young in his “Six Months’ Tour in the North of 
England ” gives us the following account of the state of the roads 
at that time (1770): “ I know not in the whole range of language 

terms sufficiently expressive to describe this infernal road. Let me 
most seriously caution all travellers who may accidentally propose to 
travel this terrible country to avoid it as they would the devil; for 
a thousand to one they break their necks or their limbs, by over¬ 
throws or breaking-downs. They will here meet with ruts, which 
I measured, actually four feet deep, and floating with mud only 
from a wet summer. What, therefore, must it be after a winter ? 
The only mending it receives is tumbling in some loose stones, 
w r hich serve no other purpose than jolting a carriage in the most 
intolerable manner. These are not merely opinions, but facts; for 
I actually passed three carts broken down in these eighteen miles 
of execrable memory.” 

England sought to improve the ill-condition of her highways by 
the establishment of a comprehensive system of turnpikes, and be¬ 
fore the beginning of this century thirty thousand miles of these 
roads had been built; but they were constructed in such an imper¬ 
fect manner that they were but little improvement on the old 
roads. Even as late as 1809 the roads answered the description of 
Mr. Young, and little improvement was effected till the advent of 
MacAdam and Telford. Contemporaries and in some respects ad¬ 
vocates of rival systems, to these two men England owes her 
present admirable system of roads; and Charles Dickens wrote: 
“ Our shops, our horses’ legs, our boots, our hearts, have all been 
benefited by the introduction of MacAdam.” 

The French and the Swiss probably have the best highways of 
any of the European countries. Until the time of Louis XIV. the 
roads of France received no more attention than did those of Eng¬ 
land. This monarch had several fine roads made in the environs of 
Paris for his personal use and pleasure. They were very wide and 
paved only in the centre. Shortly after the construction of these 
royal roads the nation began to appreciate the advantage of good 
roads,but it was not until the advent of the first Napoleon that the 
modern system of magnificent highways was inaugurated, solely for 
military purposes, and this object has never been lost sight of; so 




HISTORICAL SKETCH 


XXXV 


that, although in modern times their use as a means of communica¬ 
tion for the people accounts for their great and increasing number, 
it is largely owing to their military character that the French gov¬ 
ernment expends the enormous sums it does annually on the 
national roads. 

The material and financial prosperity, thriftiness, and content¬ 
ment of the French people has long excited the admiration of the 
world; neither internal revolution nor defeat from abroad appears 
to have entailed upon them burdens too heavy for them to bear. 
Students of economic problems ascribe this marvellous condition to 
the far-reaching and splendidly maintained system of highways, on 
which the obstacles to economical transportation have been reduced 
to the minimum. 

In the United States the highways have not improved as rapidly 
as other institutions; in fact, they are very inferior to those of 
Europe. The reason for this may be attributed to several causes, 
among which may be mentioned (1) the excellence of the railroad 
systems and waterways; (2) the indifference of those in charge of 
highway maintenance; (3) the want of appreciation of the benefits 
of good roads and the fear of increased taxation on the part of the 
rural population; (4) the dispersion of the people over large 
areas in their search for desirable localities for residence; and (5) 
the ill-effects of the system requiring the personal service of the 
rural population on the highways. 

The experience of Europe in road improvement shows that the 
highways should be taken as much as possible out of the hands of 
local authorities, and administered by either national or state gov¬ 
ernments in accordance with the needs of the people who use the 
roads; and that as the whole public is benefited by good roads, 
therefore all should pay for their improvement and maintenance 
This view of the subject is not new in the United States, for Wash¬ 
ington recommended in a letter to Patrick Henry that the roads 
of Virginia be taken away from the control of the county courts 
and be given to the State authorities. One of Hamilton's pet 
schemes was that of road improvement, and he recognized thor¬ 
oughly that roads left to local authority would never be satisfac¬ 
torily built. During the past ninety years there has been more or 
less national legislation in regard to common roads. Several very 
comprehensive measures have passed one or another of the Houses 






XXXYl 


HIGHWAY CONSTRUCTION. 


of the National Congress, but the only road of any consequence 
constructed by the government was the national road (650| miles in 
length, 80 feet in width, and macadamized for a width of 30 feet), 
which it originally was intended should go from the tide-water of the 
Atlantic Ocean to the Ohio River. It was built from Cumberland 
m Maryland to a point in Ohio several hundred miles from the 
Ohio River, and there it was allowed to stop, being finally donated 
1 o the States through which it passes. In this way ended the first 
great effort of the Federal Government to build and establish, as the 
Constitution of the United States contemplated, a system of post¬ 
roads all over the country. 

The date of the first introduction of street pavements cannot be 
determined with certainty. Livy informs us that in the year 584 
(about 170 b.c.) the censors caused the streets of Rome to be paved 
from the ox market to the temple of Venus. Streets paved with lava, 
having deep ruts worn by the wheels of chariots, and raised banks 
on each side for foot-passengers, are found at Pompeii and Hercu¬ 
laneum. 

Abderahman, the caliph of Cordova, SjDain, caused the streets of 
that city to be solidly paved, a.h. 236 (a.d. 950), and a man 
might walk after sunset ten miles in a straight line by the light of 
the public lamps. 

The date of the first introduction of pavements into London is 
unknown, but the streets of that city were not paved at the end of 
the eleventh century. It is related that in the year 1190 the 
church of St. Mary-le-Bow in Cheapside was unroofed by a 
violent wind, and that four pillars, 26 feet in length, sunk so deep 
into the ground that scarcely 4 feet of them appeared above the 
surface of the soft earth forming the street. Holborn was first 
paved in 1417, and Smithfield in 1614. The first act for paving 
and improving the City of London was passed in 1532. The 
streets were described in the simply-worded statute as "very 
foul, and full of pits and sloughs, so as to be mighty perilous and 
noyous, as well for all the king’s subjects on horseback as on foot 
with carriages” (litters). 

The capital of France was not paved in the twelfth century, for 
Rigord, the physician and historian of Philip II., relates that, the 
king standing one day at a window of his palace near the Seine 
and observing that the carriages which passed threw up the dirt 







HISTORICAL SKETCH 


XXXV11 


in such a manner that it produced a most offensive stench, his 
majesty resolved to remedy this intolerable nuisance by causing 
the streets to be paved, which was accordingly done. The orders 
for this purpose were issued by the government in the year 1184, 
and upon that occasion, it is said, the name of the city, which was 
then called Lutetia, on account of its dirtiness, was changed to that 
of Paris. 

Dijon, France, had paved streets as early as 1391, and it is re¬ 
marked by historians that after this was done dangerous diseases, 
such as dysentery, spotted fever, and others, became less frequent 
in that city. 

In the United States, Boston, Mass., appears to have been the 
first city to pave its streets, for when Josselyn visited that city in 
1G63 he found many streets paved with pebbles; and Ward said in 
1699: “ The buildings, like their women, being neat and handsome, 
and their streets, like the hearts of the male inhabitants, are paved 
with pebble.'" Drake says that the paving of the public streets 
began very early and was made of importance after 1700; the side¬ 
walks were also early paved with cobblestones and flags. 

We learn that the first regular paving of a Philadelphia street 
was due to an accident. A man on horseback being mired and 
thrown from his horse, breaking his leg, a subscription was raised 
and the street paved with pebbles from the river-bank. In 1719 
many sidewalks were being paved with brick and the cartway with 
cobblestone. 

In 1750 the grand jury represented the great need of paved 
streets, “ so as to remedy the extreme dirtiness and miry state of 
the streets;"" but the first general effort worthy of mention to pave 
the streets was made in 1761-62, and then the only means applied 
to the purpose was that produced by lotteries. 

Authority to construct toll-roads was first granted in England, 
in 1346, but their construction did not become general until 1676, 
and they were entirely abolished in 1878. 

In the United States the first toll-road company was incorpo¬ 
rated in Pennsylania in 1792, to construct and maintain an 
artificial road from Philadelphia to Lancaster, a distance of about 
70 miles. The framers of the act authorizing the construction of 
this road recognized the importance of the relation between the 
load and the width of the wheel-tire. The rate of toll was graded 






HIGHWAY CONSTRUCTION. 


xxxviii 


according to the width of the tire, and the maximum load to be 
carried by the different widths of tire was distinctly stated. 
Vehicles with tires of less breadth than four inches were not 
allowed to carry more than two and a half tons between the first 
day of December and the first day of May, and not more than three 
tons during the rest of the year. 

The act also provided for the placing of milestones and the 
erection of guide-posts at all intersecting roads, with the name of 
the place to which they led and its approximate distance in miles. 

Though considerable advance in processes and machines have 
been made during the past hundred years, the two chief factors in 
the preservation of roads so ably regulated in the above mentioned 
act are still the same, and in many cases are the cause of the evils 
we suffer from in the shape of bad highways. 





A TEEATISE ON HIGHWAY CONSTEECTION. 


CHAPTER I. 

PAVEMENTS. 

1. General Considerations. —The object of a pavement is (1) to 
secure a water-tight covering that will preserve the natural soil 
from the effects of moisture, and not, as commonly supposed, to 
support the vehicles, the weight of which and that of the covering 
material must be actually borne by the natural soil. (2) To fur¬ 
nish a smooth surface on which the force of traction will be 
reduced to the least possible amount, and over which vehicles may 
pass with safety and expedition at all seasons of the year. 

2. The Qualities essential to a good pavement may be stated as 
follows: 

(1) It should be impervious. 

(2) It should afford good foothold for horses. 

(3) It should be hard and durable, so as to resist wear and dis¬ 
integration. 

(4) It should be adapted to every grade. 

(5) It should suit every class of traffic. 

(6) It should offer the minimum resistance to traction. 

(7) It should be noiseless. 

(8) It should yield neither dust nor mud. 

(9) It should be easily cleaned. 

(10) It should be cheap. 



2 


HIGHWAY CONSTRUCTION. 


3. Interests affected in the Selection. —Of the above require¬ 
ments, numbers 2, 4, 5, and 6 affect the traffic and determine the 
cost of haulage by the limitations of loads, speed, wear and tear of 
horses and vehicles. If the surface is rough or the foothold bad, 
the weight of the load a horse can draw is decreased, thus necessi¬ 
tating the making of more trips or the employment of more horses 
and vehicles to move a given weight. A defective surface necessi¬ 
tates a reduction in the speed of movement and consequent loss 
of time; it increases the wear of horses, thus decreasing their life- 
service, and lessens the value of their current services; it also in¬ 
creases the cost of maintaining vehicles and harness. 

Numbers 7, 8, and 9 affect the occupiers of the adjacent premises, 
who suffer from the effect of dust and noise; and second, the own¬ 
ers of said premises, whose income from rents is diminished where 
these disadvantages exist. 

Numbers 3 and 10 affect the taxpayers alone, first as to the length 
of time during which the covering remains serviceable, and second 
as to the amount of the annual repairs. Number 1 affects the 
adjacent occupiers principally on hygienic grounds. Numbers 7 
and 8 affect both traffic and occupiers. 

4. Selection of Pavements. —In the selecting of the most suita¬ 
ble pavement, whether for a street or a country road, all classes of 
citizens are alike interested; for of all the systems of intercom¬ 
munication none is brought into more direct contact with the peo¬ 
ple than the public highway, and its effect upon the price of 
commodities is felt by all. Not a ton of agricultural or mechani¬ 
cal produce can reach its destination without first and last paying 
toll to the condition of the highway over which it has to be hauled; 
in the form of time, wear and tear of horses, harness, and vehicles 
thus enhancing its cost to the consumer without any increased 
benefit to the producer, who must be compensated for the cost of 
all unnecessary expenses of transportation due to the ill condition 
of the highway. 

5. Cost of Wagon Transportation. —It is apparent that but few 
people comprehend the cost of transportation by horses and wagons, 
or realize the amount of money annually wasted by the ill condi¬ 
tion of the roadways. 

Table I shows from actual observation the cost of moving a 
load of one ton a distance of one mile on level roadways with 



PAVEMENTS. 


3 


different pavements in the usual condition in which they are main¬ 
tained. The excessive amount of these charges is seen when it 
is remembered that the same goods using the roadways are now 
carried by the railroads at an average cost of t 6 q of a cent per ton- 
mile. 


TABLE I. 

•Cost of Transportation by Horses and Wagons per Ton-mile on 

Different Road-coverings. 


Iron rails . .... 


Asphalt . . 

.... 2.70 


i t 

Stone, paving, dry and in good order.. . 

... 5.33 

< 6 

t € 

“ “ ordinary condition . 

.... 12.00 

tt 

tt 

“ “ covered with mud . 

.... 21.30 

it 

it 

Broken stone, dry and in good order . 

. . . 8.00 

c c 

it 

“ “ moist “ “ “ _ 

.... 10.30 

tt 

tt 

“ “ ordinary condition . 

... 11.90 

t t 

a 

“ “ covered with mud . 

... 14.30 

tt 

tt 

“ “ ruts and mud . 

.... 26.00 

t C 

a 

Earth, dry and hard . 

.... 18.00 

i t 

it 

“ ruts and mud . 

.... 39.00 

( t 

tt 

Gravel, loose .. 

.... 51.60 

tt 

it 

“ compacted . 

.... 12.80 

t c 

it 

Plank, good condition . 

.... 8.80 

c < 

tt 

Sand, wet. 

.... 32.60 

c c 

tt 

“ dry... 

.... 64.00 

tt 

11 


6. In 1890 the railroads of the United States carried over 
600,000,000 tons of freight. Most if not all of this had to be han¬ 
dled at one or both terminals in wagons. If the distance hauled 
was but one mile and the rate per ton-mile 22£ cents, which is the 
average rate of haulage, the cost would be $133,500,000. The low 
rate of railroad transportation has been achieved by careful and 
scientific study, and by daily attention to every portion of the road¬ 
bed and rolling stock. Defective parts are instantly removed and 
new ones substituted so that the road is always in good order. But 
pavements once laid are left to batter the vehicles, and the vehi¬ 
cles, in return, to pound the pavements: little or no attention 
being paid to them until they finally become unendurable and are 
entirely renewed. Moreover, on every well-managed railroad the 
statistics of cost of transportation are the subject of the most sci¬ 
entific study, and at the end of each year it is exactly ascertained 






















4 


HIGHWAY CONSTRUCTION". 


just how much it has cost to haul a ton of freight one mile, and 
what proportion of this is for train service, what for maintenance of 
rolling stock, what for maintenance of way, and so on; whereas 
very few engineers in charge of highways have attempted to find 
out accurately what is the relative damage done to vehicles and 
horses by different kinds of pavements, what is the relative amount 
of force required to draw a unit of weight on different surfaces, 
what is the relative cost of maintaining different pavements during 
a term of years under a unit of traffic, or what is the exact propor¬ 
tion of horses falling on different surfaces. 

7. Effect of Reducing the Cost of Wagon Transportion.—If the 
cost of wagon transportation could be reduced by the improvement 
of the highways to, say, five cents per ton-mile, what would be the 
result ? It would create an annual saving of many millions of dol¬ 
lars and it would put in motion a large tonnage of various kinds of 
merchandise that cannot now be handled with profit; it would give 
a large margin of profit on many products which are now moved 
with little profit, and would directly benefit both the producer and 
the consumer. 

The cost of wagon transportation over the roads of France does 
not exceed one third the like expense in America, it being common 
in rural districts to haul three tons and in the cities from three to 
five tons net freight with one horse. 

8. Problem involved in the Selection of Pavements.—The prob¬ 
lem involved in the selection of the most suitable pavement is 
composed of the following factors: first, adaptability; second, 
desirability; third, serviceability; fourth, durability; fifth, cost. 

9. Adaptability.—The best pavement for any given roadway 
will depend altogether on local circumstances. Pavements must be 
adapted to the class of traffic that will use them. The pavement 
suitable for a road through an agricultural district will not be 
suitable for the streets of a manufacturing centre, nor will the 
covering suitable for heavy traffic be suitable for a pleasure-drive 
or a residential district. 

General experience indicates the relative fitness of the several 
materials as follows: 

For country roads, suburban streets, and pleasure-drives, broken 
stone. For streets having heavy and constant traffic, rectangular 
blocks of stone laid on a concrete foundation with the joints filled 



PAVEMENTS. 


5 


with bituminous or Portland cement grout. For streets devoted 
to retail trade and where comparative noiselessness is essential, 
asphalt, wood, or brick. 

10. Desirability. —The desirability of a pavement is its posses¬ 
sion of qualities which make it satisfactory to the people using and 
seeing it. Between two pavements alike in cost and durability, 
people will have preferences arising from the condition of their 
health, personal prejudices, and various other intangible influences, 
causing them to select one rather than the other in their respective 
streets. Such selections are often made against the demonstrated 
economies of the case, and usually in ignorance of them. When¬ 
ever one kind of pavement is more economical and satisfactory to 
use than is any other, there should not be any difference of opin¬ 
ion about securing it, either as a new pavement or in the replace¬ 
ment of an old one. 

Popular prejudices about pavements affect the prices of real 
estate upon paved streets, and so help to determine their desir¬ 
ability. A stranger’s impression of a city or town depends largely 
upon the ease with which he can go from place to place in the 
transaction of business or in the pursuit of pleasure, and he is 
pleased or displeased exactly in proportion to the smoothness of 
his journey or the ruggedness of his way. Massive business blocks, 
pretentious private residences, stately public buildings, beautiful 
parks and lawns, possess no attraction for one who is compelled to 
pick a way for his feet and keep his eyes on the ground for fear of 
stumbling over jagged stones or falling in the mud. To man and 
beast alike, the roadway that offers a few or no obstacles to easy 
travel is a delight which shortens the journey by mitigating the 
pangs of fatigue. 

To persons who ride for pleasure or for health, rough pave¬ 
ments cause great annoyance. The pleasure of fast driving in the 
parkways or roadways devoted to that purpose is defeated by the 
necessity of jolting over rough pavements until the driveway is 
reached, and in the case of invalids the rough roadways prevent 
the taking of air altogether in many cases. 

11. The economic desirability of pavements is governed by the 
ease of movement over them, and is measured by the number of 
horses or pounds of tractive force required to move a given weight, 
usually one ton, over them. The following table shows the relative 



6 


HIGHWAY CONSTRUCTION. 


tractive force required upon level roads formed of different ma¬ 
terials, asphalt being taken as the standard of excellence in this 
respect: 


TABLE II. . 

Number of Horses required to move One Ton on Different Pave- 

ments. 


Asphalt. 1.00 

Stone blocks, dry and in good order. 1.50 to 2.00 

“ “ in fair order. 2.00 “ 2.50 

“ covered with mud . 2 00 “ 2.70 

Macadam, dry and in good order.2.50 “ 3.00 

“ in a wet state. 3.30 

“ in fair order. 4.50 

“ covered with mud. 5.50 

“ with the stones loose . 5.00 “ 8.20 


See also Tables L and LI, pages 261 and 264. 

12. From Table II it is seen that to move the same load at 
the same speed and for the same length of time, with the same 
fatigue to each horse, requires from 1| to 3 horses on stone block 
pavements, and 2£ to 8£ on macadam, while for asphalt but 1 is 
required. 

If iron rails be taken .as the standard of excellence, the number 
of horses required will be as follows: 


Iron rails. . 1 

Asphalt. 1| 

Stone block, best condition. 3£ 

“ “ ordinary condition. 5 

“ “ bad “ . 8 

Macadam. 5.7 to 8 

Cobblestones, good. 6.6 “ 13.3 

“ ordinary. .25 

Earth, dry.. 20 

Sand. 40 


13. Economy of Smoothness.— From the above table the great 
economy of smoothness becomes at once apparent. But it is evident 
that, as in all lines of transportation, the greatest resistance regu¬ 
lates the load over the rest of the route, unless there be auxiliary 
power; so the continuity of the surface should remain unbroken 
by any other grade of material which would increase the resistance. 






















PAVEMENTS. 


7 


The advantages of smooth pavements to owners and users of 
horses and vehicles are enormous. With them one third greater 
loads could be moved; there would be no stuck teams, fewer wor¬ 
ried, beaten horses, fewer angry, overworked drivers, and thus fewer 
delays and interruptions to business. 

14. Serviceability.—The serviceability of a pavement is its 
quality of fitness for use. This quality is measured by the expense 
caused to the traffic using it, viz., the wear and tear of horses and 
vehicles, loss of time, etc. No statistics are available from which 
to deduce the actual cost of wear and tear. It has been estimated 
as follows: 

On cobblestones. 5 cents per mile travelled 

“ belgian block. 4 “ “ 

“ granite block. 3 “ “ 

“ wood..2.5 “ “ 

“ broken stone in first-class condition... 1.2 “ “ 

“ asphalt. 1 “ “ 

The serviceability of any pavement depends in a great measure 
upon the amount of foothold afforded by it to the horses, provided, 
however, that its surface be not so rough as to absorb too large a 
percentage of the tractive energy required to move a given load 
over it. Cobblestones afford excellent foothold, and for this reason 
are largely employed by horse-car companies for paving between 
the rails; but the resistance of their surface to motion requires the 
expenditure of about 280 pounds of tractive energy to move a load 
of 1 ton. Asphalt affords the least foothold, but the tractive force 
required to overcome the resistance it offers to motion is only about 
30 pounds per ton. 

15. Comparative Safety.—The comparison of pavements in this 
respect is the distance travelled before a horse falls. The ma¬ 
terials affording the best foothold for horses are as follows, stated 
in the order of their merit: 

(1) Earth dry and compact. 

(2) Gravel. 

(3) Broken stone (macadam). 

(4) Wood. 

(5) Sandstone and brick. 

(6) Asphalt. 

(7) Granite blocks. 









8 


HIGHWAY CONSTRUCTION. 


16. The most complete observations made in the United States 
to ascertain the prevalence of accidents on the different pavements 
were made under the direction of Capt. F. V. Greene, the results of 
which show that a horse may travel before falling on 


Asphalt (Trinidad).\ 583 miles 

Granite ...413 “ 

Wood.. 272 “ 


17. Observations for the same purpose were made in London 
under the direction of Col. Haywood. The results were as follows. 
The three classes of pavements, wood, asphalt, and stone, were ob¬ 
served as nearly as was possible under the same conditions of space, 
weather, gradients, and soundness. The result of fifty days* ob¬ 
servation showed that before meeting with an accident a horse 
would travel a far greater distance on wood than he could either 
on asphalt or stone. The following table shows the distance trav¬ 
elled by a horse before meeting with an accident: 


DRY-WEATHER DISTANCES. 

Wood. 646 miles 

Asphalt. 223 “ 

Granite. 78 “ 

DAMP-WEATHER DISTANCE. 

Wood. 193 miles 

Asphalt. 125 “ 

' Granite. 168 “ 

THOROUGHLY-WET-WEATHER DISTANCES. 

Wood. 432 miles 

Asphalt. 192 “ 

Granite. 537 “ 

Another mode of observation gave the distance travelled as 
follows: 

Wood. 446 miles 

Asphalt...... 191 “ 

Granite... .. 132 


18. The foregoing figures appear to show that 

(1) Asphalt was most slippery when merely damp, and safest 
when perfectly dry. 

(2) That granite was most slippery when dry and safest when 
wet. 


















PAVEMENTS. 


9 


(3) That wood was most slippery when damp and safest when 
dry. It will be noticed that only under a single condition, and 
that the least persistent, is granite safer than wood or asphalt, and 
that wood is safer than asphalt under all circumstances. 

Granite was least safe and wood and asphalt most safe when clean. 

19. Slight rain makes asphalt and wood more slippery than 
they are at other times. On asphalt the slipperiness begins almost 
immediately the rain commences. Wood requires more rain before 
its worst condition ensues. The slipperiness lasts longer upon 
wood, on account of its absorbent nature, than it does upon the as¬ 
phalt. When dry weather comes after the rain, then asphalt is in 
its most slippery condition and horses fall upon it very suddenly. 
On wood their efforts to save themselves are more effectual. Wood 
is also frequently in that peculiar condition of surface in which 
horses slip or slide along it without falling. A small quantity of 
dirt on asphalt makes it very slippery. In damp weather granite 
blocks become very greasy and slippery; in dry weather, if of a 
hard variety, the surface polishes and becomes rounded and the 
only foothold is by the joints between the blocks. 

In winter, during frost, asphalt is usually dry and safe; wood, 
retaining moisture, is very slippery. Under snow there is very 
little if any difference between the safety of asphalt and wood. 

20. The difference in the results obtained by Capt. Greene 
and Col. Haywood may be due in the case of the wood and stone 
pavements to climatic causes. London is more damp and foggy 
than any one of the American cities in which the traffic was ob¬ 
served, and therefore its pavements would be more slippery. The 
difference in the asphalt returns may be accounted for by the dif¬ 
ference in the character of the material. The asphalt pavements in 
London are made from natural bituminous rock, which makes a very 
smooth, hard surface, while the American pavements are made from 
natural bitumen mixed with sand, which forms a rough, granular 
surface. Moreover, these observations were made some eighteen 
years ago, at a time when asphalt was a new thing and its proper 
treatment very insufficiently understood. It was not then recog¬ 
nized that asphalt requires to be constantly and thoroughly cleansed 
in order to do justice to itself. That the number of falls on as¬ 
phalt is decreasing as its use is becoming more extended is shown 
by the following: 




10 


HIGHWAY CONSTRUCTION. 


In Berlin in 1885, 4403 horses fell on an area of 398,000 square 
yards of asphalt pavement, in 1887 the number was reduced to 
2456, while the area had increased to 485,000 square yards. 

That asphalt is but slightly more dangerous than some kinds 
of stone is shown by observations made at Paris some years ago in 
two streets, one paved with the hard sandstone much used in that 
capital, and the other with asphalt. In the street paved with stone 
one out of every 1308 horses fell, and in that paved with asphalt 
one out of every 1409 fell, 

21. Slipperiness can be cured on both wood and asphalt: on 
the asphalt by sprinkling it with sand, on the wood by sprinkling 
it with gravel. The result in both cases is dirt. The sand thrown 
on the asphalt tends to wear it out; the gravel thrown on the wood 
tends to preserve it. 

22. Kinds of Falls and their Causes.—The commonest falls on 
wood are falls on the knees, which are less likely to injure the horses 
and are less inconvenient to the traffic than other falls. Falls on 
haunches are more numerous on asphalt than on wood. Of com¬ 
plete falls there are fewest on wood and most on granite. The falls 
on asphalt are generally due to sudden pulling up and sharp turn¬ 
ing; those on granite, to the excessive width of the blocks, which 
fail to afford proper foothold. 

23. Durability.—The durability of a pavement is its quality, 
which relates to the length of time during which it is serviceable 
and not to the length of time it has been down. The only meas¬ 
ure of the durability of a pavement is the amount of traffic tonnage 
it will bear before it becomes so icorn that the cost of replacing it 
is less than the expense incurred by its use. 

24. As a pavement is a construction, it necessarily follows that 
there is a vast difference between the durability of the pavement 
and the durability of the materials of which it is made. Iron is 
eminently durable, but as a paving material it is a failure. 

25. Durability and Dirt.—The durability of a paving material 
will vary considerably with the condition of cleanliness observed. 
One inch of overlying dirt will most effectually protect the pave¬ 
ment from abrasion and indefinitely prolong its life. But the dirt 
is expensive, it injures apparel and merchandise, and is the cause 
of sickness and discomfort. In the comparison of different pave¬ 
ments no traffic should be credited to the dirty one. 



PAVEMENTS. 


11 


26. A pavement so rough and insecure that the traffic is kept 
off the road might be a most durable one, but it certainly would 
be lacking in serviceability. In a general way of speaking, the 
value of city property depends upon the volume of the traffic in 
the street upon which it is located. Ordinarily a pavement is not 
wanted by the owners of property on the street, however durable it 
may be, if it lacks serviceability; and they may not want it, even 
when it is serviceable, if it is not popular. 

27. Life of Pavements.—The life or durability of the different 
pavements under like conditions of traffic and maintenance may be 
taken as follows: 

Granite block 
Sandstone.... 

Asphalt . 

Wood. 

Limestone..., 

Brick. 

Macadam- 

28. Cost.—The question of cost is the one which usually inter¬ 
ests the taxpayers, and is probably the greatest stumbling-block in 
the attainment of good roadways. The first cost is usually charged 
against the property abutting on the highway to be improved. The 
result is that the average property-owner is always anxious for a 
pavement that costs little, because he must pay for it, not caring 
for the fact that cheap pavements soon wear out and become a 
source of endless annoyance and expense. Thus false ideas of econ¬ 
omy always have stood and undoubtedly to some extent always will 
stand in the way of realizing that the best is the cheapest. 

29. The pavement which has cost the most is not always the 
best, nor is that which has cost the least the cheapest; the one which 
is truly the cheapest is the one which makes the most profitable re¬ 
turns in proportion to the amount which has been expended upon it. 
No doubt there is a limit of cost to go beyond which would produce 
no practical benefit, but it will always be found more economical 
to spend enough to secure the best results, and it will always cost 
less in the long-run. One dollar well spent is many times more 
effective than one half the amount injudiciously expended in the 
hopeless effort to reach sufficiently good results which may look as 


12 to 30 years 
6 “ 12 “ 

10 “ 14 “ 

3 “ 7 “ 

1 “ 3 “ 

5 “ ? “ 

? 










12 


HIGHWAY CONSTRUCTION. 


well for the time, no matter how soon it may have to be done over 
again. 

30. A good roadway should cost more to build than a poor 
one, but it is often the case that the poor road costs as much as a 
good one would. But even when a good one is more expensive, it 
will be easier and cheaper to keep in repair, and will last many 
years longer, while its advantages and the saving to those who 
daily use it will much more than compensate for the extra expense 
they may have been put to in building it. 

31. Economy and Public Bodies.—The true economy for public 
bodies which never die is to secure the best, in the best possible 
manner; for the best, every essential point being considered, is the 
cheapest. If a cheap pavement is adopted, the cost to maintain it 
will be so excessive as to more than make the difference between 
its first cost and that of a first-class one. As an instance of the 
profitable results of this policy the experience of the city of Liver¬ 
pool, England, may he cited. 

After many years of experiment and the expenditure of vast 
sums of money in pavements, the corporation of Liverpool now 
points with justifiable pride to its 250 miles of the best paved 
streets in the world. 

The policy adopted by this corporation in the execution of 
public works in the best possible manner, and generally by their 
own workmen, has proved successful in every way ; and, by a 
judicious primary expenditure, the cost of maintenance of the roads, 
sewers, and other public works is reduced to a minimum, and the 
greatest economy is thereby attained. 

The laying of the impervious pavement which was adopted in 
1872 for the carriage-ways of the city has been continued up to 
date without intermission, and is still in progress, resulting in 
nearly 1,750,000 yards, superficial, of impervious carriage-way pave¬ 
ments, and a saving by the execution of this class of work unpre¬ 
cedented in municipal experience. 

The financial result can best be shown by the following: “ Deal¬ 
ing with the year 1879, under the present city engineer (Mr. Clem¬ 
ent Dunscombe, M.A., M. Inst. C. E.), the estimated expenditure for 
the general repairs to the roads in this city was £28,000 ($136,080), 
the mileage of adopted roads at that time being 226 miles. 
Concurrently with the extension of the impervious carriage-way 



PAVEMENTS. 


13 


pavements, the expenditure under this head has been reduced year 
by year till the estimated cost for the current year (1889) is only 
£8400 ($40,824), with a street mileage under repair of 254 miles. 
This reduction has not been effected, as might at first sight be 
supposed, by an increased rate under this head, due to an aug¬ 
mented expenditure of capital requiring the provision of additional 
interest and sinking fund to redeem the original debt for paving 
and like works within 23 years (from 1870, when the loan was 
effected, to 1893, when it will be paid), as the amount raised on 
paving-rate account in the year 1879 was, approximately, £17,000 
($82,620) more than in the year 1889, although the interest and 
sinking fund on the debt had increased from about £13,000 
($63,180) per annum in the year 1879 to about £47,000 ($228,420) 
per annum in the year 1889.” 

Permission is never given to private companies or persons to cut 
through the pavement in any street for any purpose. When such 
work is necessary, the corporation will do it in its own thorough 
way, and the interested parties must pay the entire cost—a regula¬ 
tion worth noting. 

With the introduction of the improved payments, it was found 
absolutely necessary, in order to attain the best results, to purchase 
the street-railroad tracks and reconstruct them in connection with 
the new pavements. Accordingly the city purchased some fifty 
miles of street-railroad tracks, and reconstructed them in a most 
substantial manner, and then rented them to the several original 
car companies at a fixed annual rental of 10 per cent on their cost. 
The city keeps the tracks in good condition. The success of these 
lines is conclusive proof that when street-car tracks are well de¬ 
signed and properly constructed they do not form the slightest 
impediment even to the narrowest-wheeled vehicles. 

32. Economic Benefit.—The economic benefit of a good road¬ 
way is comprised in its cheaper maintenance, greater and easier 
facility for travelling, thus reducing the cost of transportation, less 
cost of repairs to vehicles, less wear of horses (thus increasing the 
life and time of serviceability and enhancing the value of their 
present service), saving of time, ease and comfort to those using it. 

33. First Cost.—The cost of construction is largely controlled 
by the locality of the place, its proximity to the particular material 
used, and the character of the foundation. Tables XXVII, XXVIII,, 



14 


HIGHWAY CONSTRUCTION. 


XXIX, XXX, XXXV, XXXVI, XXXVII, XLI, XLII, and XLIII 
show the cost of different pavements in several of the principal 
cities of America. 

34. The Relative Economies of Pavements—whether of the 
same kind in different condition or different kinds in like good 
condition—are sufficiently determined by summing their cost under 
the following headings of account : 

(1) Annual interest upon first cost. 

(2) Annual expense for maintenance. 

(3) Annual cost for cleaning and sprinkling. 

(4) Annual cost for service and use. 

(5) Annual cost for consequential damages. 

35. First. —The first cost of a pavement is like any other per¬ 
manent investment, measurable for purposes of comparison by the 
amount of annual interest on the sum expended. Thus, assuming 
the worth of money to be 4$, a pavement costing $4 per square 
yard entails an annual interest loss or tax of $0.16 per square yard. 

36. Second. Maintenance.—Under this head must be included 
all outlays for repairs and renewals which are made from the time 
when the pavement is new and at its best to a time subsequent 
when, by any treatment, it is again put in equally good condition. 
The gross sum so derived divided by the number of years which 
elapse between the two dates gives an average annual cost for 
maintenance. ' 

37. Maintenance means the keeping of the pavement in a con¬ 
dition practically as good as when first laid. The cost will vary 
considerably, dependiug not only upon the material and manner in 
which it is constructed, but upon the condition of cleanliness 
observed, and the quantity and quality of the traffic using it. 

38. The prevailing opinion that no pavement is a good one 
unless when once laid it will take care of itself is erroneous; there 
is no such ])avement. All pavements are being constantly worn by 
traffic and the action of the atmosphere, and if any defects which 
appear are not quickly repaired they soon become unsatisfactory 
and are destroyed. To keep them in good repair incessant atten¬ 
tion is necessary and is consistent with economy. Yet claims are 
made that particular pavements cost little or nothing for repairs, 
simply because repairs are not made, while any one can see the 
need of them. 

39. Third. —Any pavement, to be considered as properly cared 



PAVEMENTS. 


15 


for, must be kept dustless and clean. While circumstances legiti¬ 
mately determine in many cases that streets must be cleaned at 
daily, weekly, or semi-weekly intervals, the only admissible condi¬ 
tion for the purpose of analysis of street expenses must be that of 
like requirements in both or all cases subjected to comparison. 

40. The cleansing of pavements both as regards its efficiency 
and cost depends (1) upon the character of the surface; (2) upon 
the nature of the material of which they are composed. Block 
pavements present the greatest difficulty; the joints can never be 
perfectly cleansed. The order of merit for facility of cleansing is 
(1) asphalt, (2) brick, (3) stone, (4) wood, (5) macadam. 

41. Fourth .—The annual cost for service is made up by com¬ 
bining several items of cost incidental to the use of the pavement 
for traffic; for instance, the limitation of the speed of movement, 
as in cases where a bad pavement causes slow driving and the 
consequent loss of time; or cases where the condition of a pave¬ 
ment limits the weight of the load which the horse can haul, and 
so compels the making of more trips or the employment of more 
horses and vehicles; or cases where it causes greater wear and tear 
of vehicles, of equipage, and of horses. If a vehicle is run 1500 
miles in a year and its maintenance costs $30 a year, then the cost 
of its maintenance per mile travelled is two cents. If the value of 
a team's time is, say, $1 for the legitimate time taken in going one 
mile with a load, and in consequence of bad roads it takes double 
that time, then the cost to traffic from having to use that one mile 
of bad roadway is $1 for each load. The same reasoning applies to 
circumstances where the weight of the load has to be reduced so as 
to necessitate the making of more than one trip. Again, bad pave¬ 
ments lessen not only the life-service of horses, but also the value 
of their current service. The unit of these accounts is obtained by 
first finding the cost per mile of distance travelled, which cost 
divided by 5.280 and multiplied by the unit of area gives the 
desired result. 

42. Fifth. Consequential Damages.—The determination of con¬ 
sequential damages arising from the use of defective or unsuitable 
pavements involves the consideration of a wide array of diverse 
circumstances. Rough-surfaced pavements, when in their best 
condition, afford a lodgment for organic matter composed largely 
of the urine and excrement of the animals employed upon the road- 



16 


HIGHWAY CONSTRUCTION. 


way. In warm and damp weather these matters undergo putre¬ 
factive fermentation and become the most efficient agency for 
generating and disseminating noxious vapors and disease-germs, 
now recognized as the cause of a large part of the ills afflicting man¬ 
kind. Pavements formed of porous materials are objectionable on 
the same if not even stronger grounds. 

43. Pavements productive of dust and mud are objectionable, 
and especially so on streets devoted to retail trade. If this particu¬ 
lar disadvantage be appraised at so small a sum per lineal foot of 
frontage as $1.50 per month, or six cents per day, it exceeds the cost 
of the best quality of pavement free from these disadvantages. 
Rough-surfaced pavements are noisy under traffic and insufferable 
to nervous invalids, and much nervous sickness is attributable to 
them. To all persons interested in nervous invalids this damage 
from noisy pavements is rated as being far greater than would be 
the cost of substituting the best quality of noiseless pavement; but 
there are, under many circumstances, specific financial losses, meas¬ 
urable in dollars and cents, dependent upon the use of rough, noisy 
pavements. They reduce the rental value of buildings and offices 
situated upon streets so paved, offices devoted to pursuits wherein 
exhausting brain-work is required. In such locations quietness is 
almost indispensable, and no question about the cost of a noiseless 
pavement weighs against its possession. When an investigator has 
done the best he can to determine such a summary of costs of a 
pavement, he may divide the amount of annual tonnage of the street 
traffic by the amount of annual costs and know what number of 
tons of traffic are borne for each cent of the average annual cost, 
which is the crucial test for any comparison, as follows: 

(1) Annual interest upon the first cost.$ 

(2) Average annual expense for maintenance and renewal. 

(3) Annual cost for custody (sprinkling and cleaning). 

(4) Annual cost of service and use . 

(5) Annual cost of consequential damages.,. 

Amount of average annual cost. 

Annual tonnage of traffic... 

Tons of traffic for each cent of cost. 

44. Gross Cost of Pavements.—Since the cost of a pavement 
depends upon the material of which it is formed, the width of the 
roadway, the extent and nature of the traffic, the condition of 











PAVEMENTS. 


17 


repair and cleanliness in which it is maintained, it follows that in 
no two streets is the endurance or the cost the same, and the differ¬ 
ence between the highest and lowest periods of endurance and 
amount of cost is very considerable. 

The comparative cost of various street pavements in Liverpool, 
including interest on first cost, sinking fund, maintenance, and 
cleaning, when reduced to a uniform standard traffic of 100,000 
tons per annum for each yard in width of the carriage-way, is given 
by Mr. Deacon as follows: 

Per Square Yard per Annum. 


Block pavements of hard granites. $0.23 

“ “ “ softer “ .. 0.28 

Bituminous concrete. 0.35 

Wood pavement. 0.53 

Macadam, on pitch foundation. 0,71 


Taking the standard of traffic at 40,000 tons per annum, for each 
yard in width the cost for the last three pavements is: 

Bituminous concrete. 0.27 

Wood. 0- 41 

Macadam... 0.4< 

Asphalt may be placed between wood and bituminous concrete, 
in the above order. These comparisons show the high cost of a 
macadamized surface in a street where traffic is great; and however 
well it may be maintained, it is much dirtier and dustier than any 
other pavement, though it is superior to them all in safety, and to 
block pavements in the matter of noise. 

Table III shows the approximate comparative gross cost of 
various pavements in the L nited States for a period of fifty years, 
the pavement at the end of that period to be in as good condition 
as when first laid. 

45. Traffic Census.—Comparison of pavements in respect to 
their gross cost can be effected only by comparing the gross traffic 
tonnage which each will bear for a unit of cost. As this can bo 
ascertained only by direct observation, it is desirable that engineers 
in charge of roads and streets find out accurately the traffic tonnage, 
the amount of force recjuired to draw a unit of weight oaci differ- 
ent surfaces in like condition, the cost of maintaining diffeient 
coverings during a given period under a unit of traffic tonnage, the 











18 


HIGHWAY CONSTRUCTION. 


TABLE III. 

Comparison of the Gross Cost of Pavements for a Period of 50 Years. 




Cost per Square Yard. 


Granite 

Block. 

Asphalt. 

Wood. 

Brick. 

Foundation, 6 in. concrete. 

$1.00 

$1.00 

$1.00 

$1.00 

Materials, labor, etc . 

3.25 

2.50 

1.40 

1.80 

Total first cost. 

4.25 

3.50 

2.40 

2.80 

Interest on materials and sinking fund, 
50 yrs. @4$ . 

26.00 

20.00 

11.20 

14.40 

Interest on foundation @4 % . ... 

2.00 

2.00 

2.00 

2.00 

Maintenance, 50 years .. 

2.50 

4.50 

7.50 

2.50 

Cleaning, etc., 50 years .. 

5.00 

1.00 

6.00 

2.50 

3 renewals of surface -$3.25 . 

9.75 

.... 

• • • • 

• • • « 

5 “ “ @ 2.50. 

• • • • 

12.50 

• ♦ • • 

» • • • 

12 “ @ 1.40 . 

• • • • 

• • • • 

16.80 

• • • • 

8 “ @ 1.80 . 

• • • • 

» • • • 


14.40 

Cost of service .(estimated at) 

30.00 

10.00 

20.00 

15.00 

“ “ consequential damages ( “ “) 

10.00 

1.00 

1.50 

2.00 

Total. 

89.50 

54.50 

67.40 

55.60 

Less value of foundation. 

1.00 

1.00 

1.00 

1.00 

Less value of old material. 

88.50 

1.00 

53.50 

.10 

66.40 

54.60 

.25 

-v- 50) 

87.50 

53.40 

66.40 

54.35 

Annual gross cost. 

1.75 

1.068 

1.33 

1.087 


relative safety of different surfaces, and the damage done to vehicles 
and horses by different pavements. These items should be care¬ 
fully observed and recorded. As the amount of travel is variable, 
the observations should be made for a certain period on con¬ 
secutive days, and should he repeated at different seasons of the 
year. 

46. The most extensive observations on this subject in the 
United States were made under the direction of Capt. F. Y. Greene, 
member of the American Society of Civil Engineers. The method 
of observing and recording was as follows: “ The observations were 
made on six consecutive days (Sundays omitted) at the same place, 
and were continuous from 7 a.m. to 7 P.M., except when darkness 
prevented. No addition was made for this omission, nor for night 
traffic.” 























































PAVEMENTS. 


19 


The printed instructions issued to each observer contained the 
following rules as a guide in estimating weights: 

Less than 1 ton. 

1-horse carriages, empty or loaded. 

1-horse wagons, empty or light loaded. 

1-horse carts, empty. 

Between 1 and 3 tons. 

1-horse wagons, heavy loaded. 

1- horse carts, loaded. 

2- horse wagons, empty or light loaded. 

Over 3 tons. 

Wagons and trucks drawn by two or more horses and heavy loaded. 

“ Special note will be made, in the column of Remarks, of any 
unusually heavy loads, such as 6-horse trucks loaded with stone or 
iron, and an estimate given of their weight.” 

The weight and number of the horses was disregarded, because 
Capt. Greene wished to make comparison with English reports in 
which their weight was disregarded. Tlieir weight should he in¬ 
cluded in all observations , as the action of tlieir feet is an impor¬ 
tant factor in the wear of pavements. 

47. Capt. Greene assigned the following weights to each class 
of vehicles: 

Light-weight vehicles one-half ton each, including their load; 
medium weight two tons, and the heavy weight four tons. 

The weight to be assigned to each class of vehicles had better 
be ascertained by occasionally weighing a typical vehicle and its 
load. The weight of horses may be taken at one-half ton each. 

48. Form of Traffic Census. 

Traffic Census 

of.Street. 

Class of pavement. 

Condition... 

Width between curbs . 

Date of observation. 

State of the weather. 

Temperature... 

Name of observer. . 












20 


HIGHWAY CONSTRUCTION. 


Hours of Observation. 


Classification 


of Vehicles. 

6 to 7. 

7 to 8. 

8 to 9. 

9 to 10. 

10 to 11. 

11 to 12. 

12 to 1. 

1-horse light. 

1- “ loaded . 

2- “ light. 

2- “ loaded. 

3- “ light.. 

3- ‘ ‘ loaded. 

4- “ light. 

4- “ loaded. 

Led horses, No. of_ 

Totals... 















Number of falls. 

Remarks. 
























49. To obtain tonnage, multiply the total number of vehicles 
in each class by the tveights assigned to that class, and adding to¬ 
gether the products the total vehicular tonnage is ascertained, 
which divided by the width between curbs and the number of days 
of observation gives the average daily tonnage per foot of width. 

Under Condition note the state of repair and cleanliness; 
whether the surface is dry, damp, or greasy. Under Falls note the 
kind, whether on knees, haunches, or complete, and if possible the 
cause. 

“ The average tonnage per vehicle is an almost infallible indi¬ 
cator of the character of the street, i.e., whether devoted to resi¬ 
dential or business purposes. It ranges from (b68 tons on Fifth 
Avenue, New York City, to 2.08 tons on a portion of Wabash Ave¬ 
nue, Chicago. The same character is indicated by the proportions 
of light and heavy vehicles in the street. On Fifth Avenue, New 
York, for instance, 91# of all the vehicles weigh less than one ton, 
while on abash Avenue only 25# of them have so little weight. 
The general average for all cities is as follows: Less than 1 ton, 67#; 
between 1 and 3, 26#; more than 3 tons, 7#. The average tonnage 
per foot of width in each city, so far a> here observed, varies from 
151 in New York to 30 in Buffalo, and the general average is 77. 
For all the cities observed the average daily tonnage per foot of 
width is 77, and varies from 273 tons on Broadway, New York, to 
7 tons on a granite street in St. Louis. The average weight per 
vehicle is, for all cities, 1.15 tons. The average width of the 
streets between curbs is 44 feet/’ 

In London the traffic on some of the asphalt- and wood-paved 
streets exceeds 400 tons per foot of width per day. 


































































PAVEMENTS. 


21 


In Liverpool granite-block pavements sustain a daily traffic 
tonnage per foot of width of from 400 to 500 tons. 

The comparative rank of pavements in the order of their merit 
is shown in Table IV. 


TABLE IV. 

Comparative Rank of Pavements, named in the Order of their 

Merit. 


Order 

of 

Merit. 

Durability. 

Service¬ 

ability. 

Hygienic 

Fitness. 

Service 

on 

Grades. 

Gross 

Annual 

Cost. 

Facility 

for 

Cleansing. 

1 

Granite 

Asphalt 

Asphalt 

Granite 

Asphalt 

Asphalt 

2 

Asphalt 

Brick 

Brick 

, Brick 

Brick 

Brick 

3 

Brick 

Wood 

Granite 

Wood 

Wood 

Granite 

4 

Wood 

Granite 

Wood 

Asphalt 

Granite 

Wood 


50. Guaranteeing Pavements.—To secure pavements that shall 
be durable and serviceable, the municipal authorities often require 
the contractors to guarantee their pavements for a term, usually, of 
five years, under provisions calling for maintenance in good condi¬ 
tion during that period of time and for final delivery in good or¬ 
der. Such contracts involve two kinds of service, that of construc¬ 
tion, and of maintenance for a limited period. In the latter the 
conditions are exacted indiscriminately alike on streets with heavy 
traffic and on those with very light traffic, and thereby become 
sometimes burdensome, unless the same contractor paves so many 
streets of all kinds as to correct the inequality by securing of fair 
average traffic condition. The correct policy to pursue in contract¬ 
ing for maintenance would be to measure the service of the pave¬ 
ment by the tonnage rather than by the years. To do so equitably 
the city needs information about the traffic, which it can obtain 
only by having a traffic census taken as described in Art. 45. 

51. Many contracts for street pavements in some European 
cities have provided for the construction and the maintenance of 
the pavements for long terms, say of twenty years, payments to 
be made in equal annual instalments throughout the term. Such 
arrangements appeared at first to be very favorable, owing to the 
first payments being so much less than they otherwise would be 
for the whole cost of construction. The pro-rata annual payments 





















HIGHWAY CONSTRUCTION. 


provided for the interest and risks of various kinds, with contrac¬ 
tors’ profits thereon, in addition to the direct outlays for construc¬ 
tion and repairs, so that the final outcome was unsatisfactory to 
both parties to the contract. The prevailing custom in this coun¬ 
try is to pay the cost of construction of a pavement as soon as com¬ 
pleted. Two methods of meeting the expense of maintenance are 
followed. In one the municipality meets the annual requirements 
as they occur, and in the other, under contract for a term, say, of 
ten or twenty years, the contractor, for equal annual payments, is 
required to keep the pavement and turn it over to his successor in 
good condition at the expiration of the contract. 

In the city of New York the guarantee period for asphalt pave¬ 
ments is fifteen years, during which payments are made as follows: 
on completion of the work seventy per cent of the cost; ac the ex¬ 
piration of five years three per cent is paid yearly for the period of 
ten years. 

52. This annual payment has to cover the contingency of the 
contractor’s being at the expense of completely renewing the pave¬ 
ment. The equal annual amounts paid on contracts for mainte¬ 
nance, as just explained, include two funds, one of repair accounts 
and the other a sinking fund, intended to meet the cost of renew¬ 
ing the pavement, which must be done if the contract is for a long 
term of years. 

53. If an attempt is made to separate, for each year, the pro¬ 
portion of the annual payment which should provide for each of 
the two purposes, it would be found that the earlier years would be 
contributing little or nothing for repairs, as, the pavement being 
new, they would not be required, but the proportion so applied 
would increase gradually, and at last consume nearly all the annual 
payment. 

54. The justification of contracts for the continuous mainte¬ 
nance of pavements is in the advantage gained from having some 
one admittedly responsible for their condition and more amenable 
to discipline than are city officials for neglect. With this consid¬ 
eration in mind each community can determine whether it is to its 
advantage or not to contract for such maintenance. 

55. Destruction of Pavements.—The most serious cause of the 
destruction of street pavements is the frequency with which they 
are torn up for the introduction and repairing of underground 
pipes, and no pavement can be designed which will withstand such 
frequent disturbance. The only radical remedy for this evil is a 




PAVEMENTS. 


23 


ver Y costly one in its first inauguration, but it is one that would be 
economical in the end, and that is a subway or series of subways 
under our roadways. 

56. The amount of money wasted in continually opening up 
the streets, digging, bracing, and refilling, is a considerable item, 
not counting the interference with travel and business, and would 
be sufficient to cover the interest on the cost of the subways. The 
waste, being distributed through many companies, is not sufficiently 
felt to cause a reconstruction. The streets of New York were 
opened 27,088 times in 1890 by the gas, steam-supply, and other 
companies, and during 1894 17,475 openings were made, in con¬ 
nection with which there were relaid 27,500 square yards of asphalt 
pavement, and 166,000 square yards of granite pavement. 

In Washington, D. C., during 1893, the total surface of pave¬ 
ment removed and restored in connection with openings in the 
streets was 19,652 square yards, at a cost of 147,594.83. 

57. Under the best municipal administrations of Europe neither 
corporations nor individuals are permitted to disturb the pave¬ 
ments. All removals and restorations are done by the city^s own 
employes, upon the deposit, by the parties who require the streets 
to be opened, of a sufficient sum to cover the expense for each 
piece of paving done, at a fixed price per yard according to the 
kind of pavement. 

Moreover, interference with the pavements is of rare occur¬ 
rence, for the companies having pipes underground are required to 
thoroughly examine and reinstate their mains and services concur¬ 
rently with the paving of a street, of the execution of which due 
notice is given them by the city. Such regulations are quite prac¬ 
tical, and there can be no hardship in requiring American compa¬ 
nies to pay for like work. 

In New York the Department of Public Works has an organ¬ 
ized system of supervision to insure the proper restoration of the 
pavements torn up by private corporations. The companies or in¬ 
dividuals making the openings are required to pay the cost of in¬ 
spection as well as the cost of restoring the pavement. 

It is stated that in Victoria Street, one of London’s busiest 
thoroughfares, not a single stone has been disturbed from the car¬ 
riage-way in twenty-five years. This street, as well as many others, 
has a subway in which are contained the gas and water pipes and 
upwards of six conduits for telegraph and electric wires. 





CHAPTER II. 


MATERIALS EMPLOYED IN THE CONSTRUCTION OF 

PAVEMENTS. 

58. Selection of Paving Material.—The materials most com¬ 
monly used for pavements are stone in the form of blocks and 
broken fragments: wood in the form of blocks and plank, as¬ 
phalt in two forms,—sheet and block,—and clay in the form of 
brick. 

59. In considerinsr the relative fitness of the various materials, 
the following physical and chemical qualities must be sought for: 

(1) Hardness, or that disposition of a solid which renders it 
difficult to displace its parts among themselves. 

(2) Toughness, or that quality by which it will endure light but 
rapid blows without breaking. 

(3) Ability to withstand the destructive action of the weather, 
and probably some organic acids produced by the decomposition of 
excretal matters, always present upon roadways in use. 

(4) The porosity, or water-absorbing capacity, is of considerable 
importance. There is perhaps no more potent disintegrator in 
nature than frost, and it may be accepted as fact that of two rocks 
which are to be exposed to frost, the one most absorbent of water 
will be the least durable. 

60. Breaking and Crushing Tests possess no definite value in 
determining upon the fitness of a material for paving purposes. It 
is an elementary fact in mechanics that a body may bear an enor¬ 
mous crushing strain gradually applied and yet be readily broken 
by a smart blow from a light hammer. Taking the ascertained 
breaking and crushing strains as lying between 3^- and 7 tons per 
square inch, it may be safely said that no such strains are ever 
brought to bear upon any single inch of roadway in practice, not 

24 


MATERIALS EMPLOYED IN THE CONSTRUCT [ON OF PAVEMENTS. 25 


even during the passage of a ten-ton roller. The direct pressure or 
strain as applied in a testing-machine has no resemblance to the 
quick blows of horses’ hoofs, much less to the abrading action of 
wheels. 

61. Methods of Testing Durability.—The only true test of the 
fitness of any material for paving is by an experimental trial upon 
a certain length of roadway under a unit of traffic. The “ Rat¬ 
tier ” tests now much employed to test the quality of bricks for 
paving do not fairly represent the condition of the materials in the 
pavement; in the latter the material is supported on all sides but 
one, and is subjected to pressure and percussion on this side, while 
in the “ Rattler ” tests the materials are thrown into violent colli¬ 
sion with large pieces of iron weighing anywhere from five to fif¬ 
teen pounds. It is evident that under this treatment the corners 
of the material will readily succumb, and the wear in consequence 
will be much greater and of a different nature than it would be 
under actual conditions. The methods adopted for testing any 
material should represent as nearly as possible the requirements of 
practical use. 

62. The following plan of testing the comparative value of 
paving-stones is adopted at the Paris Laboratory for Testing Mate¬ 
rials. While it may be questioned whether this method is superior 
to the “ Rattler” test, it indicates foreign appreciation of the fact 
that the “ Rattler” test is not what it should be. The stone or other 
samples are clamped to a horizontal plate revolving round a verti¬ 
cal spindle and brought to bear with equal pressure against a simi¬ 
larly disposed revolving plate of cast-iron. Along with the sam¬ 
ples to be tested is placed a specimen of the standard material, 
which is Yvette sandstone. The coefficient of wear is the propor¬ 
tion between the volumes worn, which is ascertained by weighing 
the specimens and determining the volume from this weight. The 
coefficient for first-class materials is from 1 to 1.40, and for second- 
class materials from 1.40 to 2.40. If the wear is greater than that 
represented by the coefficients, the material is rejected. 

63. At St. Louis, Mo., some years ago, strips of different pave¬ 
ments 22 inches wide and 8 feet long were laid down as a test, and 
a two-wheeled cart with tires 2J inches wide, and loaded to two tons, 
or 800 pounds per inch width of tire, was rolled back and forth by 
machinery. The heaviest traffic at that time in St. Louis was 75 





26 


HIGHWAY CONSTRUCTION. 


tons per day per foot of width, and the average for business streets 
was 35 tons. Estimating the effect of horses* shoes at one third of 
this amount, 50 tons per foot were taken as a standard. The sam¬ 
ples were weighed before and after testing, and were subjected to 
an amount of travel by the above cart equivalent to eight and one 
half years on the street. 

The total abrasion of the fire-brick pavement was 9$, or a depth 
of J of an inch, but about one half of the bricks were broken. As- 
phaltum blocks under the same test wore 14$, and but one was 
broken. Broken stone lost 1$ under a traffic of 12.7 tons per foot 
of width. Broken stone and sand lost 1$ under 16 tons per foot. 
Limestone blocks lost 1$ under 4400 tons per foot of width. Wood 
blocks lost 1$ under 12,900 tons per foot, and the granite blocks 
lost 1$ under 70,000 tons. 

The action of the elements was not taken into consideration; it 
would undoubtedlv increase the wear of the several materials. 

64. Absorptive Power of Stones, etc.—All materials absorb water 
to a greater or less extent, and their durability is much affected by 
their absorbing capacity. This capacity depends largely on the den¬ 
sity, a dense stone absorbing less than a light and more porous 
one. The absorbing capacity is a matter of much importance, es¬ 
pecially in cold climates. The water absorbed, on freezing, tends 
by its expansion to disintegrate the stone. It has been said that 
the act of freezing is equivalent to the blow of a ten-ton hammer 
on every square inch of surface. Whether this be so or not, the 
continued expansion and contraction of a porous stone is quite 
sufficient to disintegrate it, and this disintegration will be the 
greater the more water the stone contains. 


TABLE Y. 


Absorptive Power of Stones, etc. 


Granites. 

Marbles. 

Limestones_ 

Sandstones. 

Brick, common 
“ paving. 

Mortars. 

Wood. 

Asphalt. 


Percentage of water absorbed. 


0.066 to 0-155 
0.08 “ 0.16 
0.20 “ 5.00 
0.41 “ 5.48 
2.00 “ 25.00 
0.15 “ 8.00 
10.00 “ 50.00 
0.16 " 9.00 
Impervious 












MATERIALS EMPLOYED IN' THE CONSTRUCTION OF PAVEMENTS. 27 


Stones that have already begun to decompose absorb a much 
larger quantity of water than those fresh from the quarry, and de¬ 
cay will be more rapid. Other things being equal, the less the 
absorption the better the stone or brick. 

65. Description of Materials.—Granite is an unstratified or 
igneous rock, composed of silica or quartz, feldspar, and mica. In 
addition to tiiese essential constituents, one or more accessory 
minerals may be present; the more commonly occurring are horn¬ 
blende, pyroxene, epidote, garnet, tourmaline, magnetite, pyrite, 
and graphite. And the character of the rock is often determined 
by the presence of these accessory constituents in quantity. 

Granite varies in texture from very fine and homogeneous to 
coarse porphyritic rocks in which the individual grains are an inch 
or more in length. The color is also dependent upon the min¬ 
erals present: if the feldspar is the orthoclase (potash-spar), it com¬ 
municates a red color; the soda-spar produces gray. The mica 
also plays an important part in the modification of color: if it is the 
white muscovite, it produces no change; but if the black biotite 
mica be present, it modifies the color accordingly. Hornblende 
gives a dark mottled appearance; pyroxene as augite also gives a 
darker appearance; epidote communicates a green color. 

The durability of the granites is closely related to their miner- 
alogical composition. The presence or absence of certain species 
influences the hardness and homogeneous nature of the stone. Al¬ 
though popularly regarded as the most durable stone, there are 
some notable exceptions. 

Tlie quartzose, feldspathic, and micaceous granites are unsuit¬ 
able for paving purposes. The quartzose are too brittle, the felds¬ 
pathic are too easily decomposed. When the feldspar is in excess 
the granite rapidly decays and disintegrates in consequence of the 
action of air and water on the feldspar, the potash of which seems 
to be. removed, and the residue falls into a white powder composed 
chiefly of silica aud alumina. The micaceous are too easily lami¬ 
nated. 

The term “ granite ” as popularly used is not restricted to rock 
species of this name in geological nomenclature, but includes what 
are known as gneisses (foliated and bedded granites, syenite, 
gabbro, and other crystalline rocks whose uses are the same); in 
fact, the similar adaptability and use have brought these latter 



28 


HIGHWAY CONSTRUCTION. 


species into the class of granites. The term is often improperly 
applied to the diabases or trap-rocks. 

66. Syenite differs from granite in having more hornblende, 
with some plagioclase, feldspar, and mica, and little or no quartz. 
(It is called syenite because it was first found in the island of 
Syene in Egypt.) It is massive and its occurrence is like that of 
granite. It furnishes the best material for paving-blocks, and is 
better in proportion to the darkness of color and the predominance 
of hornblende. 

67. The Sioux Falls stone, much used for paving in the West, 
is a quartzite, close-grained, non-absorbent, and frost-proof. It 
does not break evenly as granite and sandstone. 

68. The gneiss, quartz, and silicious rocks, though hard, are 
too brittle and deficient in toughness for paving purposes. 

69. Table VI. shows the specific gravity, weight, and resist¬ 
ance to crushing of various granites. 


TABLE VI. 

Specific Gravity, Weight, and Resistance to Crushing of Various 

Granites. 


Localities. 

Specific 

Gravity. 

Average Weight, 
pounds per 
cubic foot. 

Resistance to 
Crushing, pounds 
per square inch. 

Kirtland Rocks, Conn. 

2.66 

166 

35,000 

Lord’s Island, Conn. 



24,000 

Chaumont Bay, N. Y.,. 

2 65 

162.2 

22,700 

Mystic River, Conn. 

2.63 

164.4 

22,250 

Sharkey’s Quarry, Me. 

2.72 


22,125 

Richmond, Va. 



21,250 

Huron Island, Mich. 



20,650 

Rockport, Mass. 

2.61 

163.2 

19,750 

Port Deposit, Md. 



19,750 

Quincy, Mass. 

2.66 

166.2 

19.500 

Duluth, Minn. 



19,000 

Hurricane Island, Me. 

2.67 

166.9 

15,000 

Mount Sorrel, England. 

2.67 

167 

12,800 

Bay of Fundy, Canada. 



11,916 

Aberdeen, Scotland (gray). 

2.62 

163 

10,900 

“ (red). 

2.62 

165 


Dublin, Ireland.. 



10,450 

New Haven, Conn. 



9,750 

Cornish, Wales. 

2.66 

166 

6,300 

Patapsco, Md. 

2.64 

163 

5,340 

— 







































MATERIALS EMPLOYED IN THE CONSTRUCTION OF PAVEMENTS. 29 


70. Table VII shows the amount of production and value of 
granite for street purposes throughout the United States for the 
year 1889. From this table it appears that the number of blocks 
used for paving amounted to nearly 62,000,000; that the value per 
thousand varies from $32.22 in Wisconsin to $78.67 in Delaware. 

TABLE VII. 

Production and Value of Granite for Street Uses in 1889.* 


States. 

Cubic feet, 
including 
Paviug- 
blocks. 

Value. 

including 

Paving- 

blocks. 

Value 

per 

cubic 

foot. 

Number 

of 

Paving- 

blocks. 

Value 

of 

Paving- 

blocks. 

Value 

per 

thou¬ 

sand. 

California. 

Colorado. 

3,284,232 

1,100 

567,860 

$551,613 

230 

$0.17 

0.21 

7,303,321 

$297,236 

$40.70 

Connecticut. 

109,261 

0.19 

761,100 

40,683 

53.45 

Delaware. 

155,500 

67,202 

0.43 

104,333 

8,208 

78.67 

Georgia. 

658,603 

250,634 

0.38 

1,599,952 

84,951 

53.10 

Maine. 

3,736,541 

927,949 

0.25 

17,704,915 

824,113 

46.55 

Maryland. 

1,051,010 

125,958 

0.12 

286,950 

10,310 

35.93 

Massachusetts... 

1,475,093 

466,147 

0.32 

6,106,016 

378,627 

62.01 

Minnesota. 

338,610 

141,554 

0.42 

1,239,000 

68,045 

54.92 

Missouri. 

871,209 

216,986 

0 25 

4,323,130 

216,986 

50.19 

New Hampshire. 

1,157,992 

252,256 

0.22 

2,043,739 

87,569 

42.85 

New Jersey. 

2,089,796 

236,310 

0.11 

3,999,912 

168,555 

42.14 

New r York. 

247,902 

51,062 

0.21 

587,120 

26,962 

45.92 

North Carolina.. 

221,820 

42,605 

0.19 

775,000 

34,200 

44.13 

Oregon. 

117,400 

30,200 

0.26 

587,000 

30,200 

51.45 

Pennsylvania.... 

1,996,486 

368,323 

0.18 

3,836,127 

241,793 

63.03 

Rhode Island.... 
South Carolina.. 

213,477 

94,489 

65,817 

34,016 

0.31 

0.36 

781,765 

45,817 

58.61 

South Dakota... 

601,000 

170,695 

0.28 

3,017,500 

170,694 

56.57 

Vermont. 

231,128 

48,323 

0 21 

883,096 

45.643 

51.69 

Virginia . 

286,946 

75,925 

0.26 

342,895 

18,505 

53.97 

AVisconsin. 

1,285,000 

223,825 

0.17 

5,540,000 

179,075 

32.32 

Total. 

20,683,244 

$4,456,891 

$0.22 

61,822,871 

$2,978,172 

$48.17 


* 11 tli U. S. Census. 


71. Value of Granite Blocks.—In the most important States 
which produce paving blocks, namely, California, Maine, Massa¬ 
chusetts, Missouri, New Jersey, and Pennsylvania, the value varies 
from $40 to something over $60 per thousand. The variation in 
the price for these States, in all of which the production of paving- 
blocks has been going on for some time, is due to the quality of the 
stone used for these purposes, and also to the special caie observed 
in trimming blocks to certain definite sizes. In some localities 
surface rock of inferior quality is broken up into paving-blocks, 















































30 


HIGHWAY CONSTRUCTION. 


which are sold at low prices. In a number of cities considerable 
care is taken by the municipal authorities in the selection of the 
granite for paving material. This care is exercised both with 
reference to the quality of the stone and to invariability of size, 
and consequently the price paid is in some cases markedly higher 
than that paid in other cities more indifferent in regard to the 
material employed. 

72. The following list is presented for the purpose of showing 
the various uses of granite for street and road construction: 

Paving-blocks. Basin-heads. 

Curbing. Crossing-stones. 

Flagging. Gutter-stones. 

Crushed for artificial stone; broken for concrete. 

73. Manufacture of Granite Paving-blocks.—The manufacture 
of paving-blocks varies in many of its details from the ordinary 
methods of granite-cutting. The high skill and fine workmanship 
of the stone-cutter are not needed, but a quickness in seeing and 
taking advantage of the directions of cleavage, as well as a deftness 
in handling the necessary tools, is requisite. 

The tools used for making blocks are knapping-hammers, 
opening-hammers, reels, chisels, and for initial splits drills, wedges, 
and half-rounds. When the block-maker quarries his own stock it 
is called “ motion work,” and the same process is used as in quarry¬ 
ing stone for other purposes, except that, as large blocks are not 
required, most of it can be done with plug and feather. 

Slabs, having been split out in the usual manner to sizes that 
may be easily turned over and handled by one man, are subdivided 
into pieces corresponding approximately to the dimensions of the 
required blocks. This is done by striking repeated blows upon the 
rock along the line of the desired break with heavy knapping and 
opening hammers. When a break is to be made crosswise the 
grain, it is frequently necessary to chisel a light groove across one 
face, and commonly across the adjacent sides, to guide the fracture 
produced by striking on the opposite surface with the opening- 
hammer. Good splits can, however, be made along either the rift 
or grain by the skilful use of the opening-hammer alone. Blocks 
broken out in the manner described are trimmed and finished with 
the reel, which is a hand-hammer having a long, flat steel head 
attached to a short handle. Block-makers become very expert in 



MATERIALS EMPLOYED IN THE CONSTRUCTION OF PAVEMENTS. 31 


che use of this tool, and without making any measurements turn 
out in a surprisingly short time a large number of blocks. In 
Maine, which is far ahead of any other State in the number of 
blocks made, the entire product of many quarries is used for this 
purpose exclusively. This is also the case in California, which 
comes second, though the blocks are manufactured chiefly from the 
surface “boulders” or detached masses of basalt so common in 
Sonoma County. Other quarries, however, in various parts of the 
country utilize only the “ grout,” small or irregular-shaped pieces, 
for making paving-blocks, and haul the stock to the breakers, who 
work in sheds; but the greatest number of blocks are made on the 
spot where the rock is quarried, the workmen being protected 
during the hottest months by a temporarily spread canvas fly. 

Blocks are counted as they are thrown into the cart which is 
usually needed to haul them to the shipping point. Several paving- 
block quarries in Maine are situated on steep mountain-slopes so 
near water communication that blocks may be slid in long board 
chutes from the quarry directly into the hold of the vessel used 
for their transportation. 

Paving breakers seldom work by the day, but are paid a certain 
sum per thousand for making the blocks; the price paid in 1889 
ranging from $22 to $30 according to the size of block made, kind 
of stone used, locality, and whether the tools were furnished and 
the blocks quarried by their employers. Workmen using their own 
tools are commonly paid one dollar more per thousand for the 
blocks made; and when they quarry the stock they use, from $2 
to $5 per thousand is allowed in addition. 

74. Sandstones are rocks made up of grains of sand which are 
cemented together by silicious, ferruginous, calcareous, or argilla¬ 
ceous material. From the nature of the cementing material the 
rocks are variously designated as ferruginous, calcareous, etc. In 
most cases the cementing material determines the color. The va¬ 
rious shades of red and yellow depend upon the iron oxides. The 
purple tints are said to be due to oxide of manganese. The gray 
and blue tints are produced by iron in the form of ferrous oxide or 
carbonate. 

75. The hardness, strength, and durability depend upon the 
nature of the cementing material. If the cementing material be 
one which decomposes readily, as in the argillaceous and calcareous 
varieties, the whole mass is soon reduced to sand. 





32 


HIGHWAY CONSTRUCTION* 


76. Sandstones are widely distributed, and they represent all of 
the geological periods, from the oldest to the most recent forma* 
tions. 

77. The sandstones obtained from the Upper Silurian and the 
Lower Carboniferous formations are much used in the form of blocks 
for street paving in the Lake and Western cities. They are durable 
and do not become smooth or slippery when wet, but in the form 
of fragments for broken stone roads they are useless. 

78. Hudson River Bluestone.—The term “ Hudson River blue- 
stone” is used to designate the blue, fine-grained, compact, and 
even-bedded sandstone which is so largely employed for flagging 
and curbing in the cities and towns of New York and neighboring 
States. 

The color is predominantly dark gray and hence (more by con¬ 
trast with the red sandstone) a “ bluestone.” 

In texture the range is from the fine shaly or argillaceous to 
the highly silicious and even conglomerate rock. 

The best bluestone is rather fine-grained and not very plainly 
laminated, and its mass is nearly all silica or quartz which is ce¬ 
mented tegether by a silicious paste and contains very little argil- 
laceous matter. 

It is so compact as not to absorb moisture to any extent, and 
hence soon dries after rain or ice; it has the hardness to resist 
abrasion and wears well; it is even-bedded and thus presents a good 


TABLE VIII. 
Analysis of Sandstone. 


Kind of 
Stone. 

Locality. 

Silica. 

Alumina. 

Iron Oxides. 

® 

SB 

® . 
c ® 
an 

a O 

S 

Lime. 

Magnesia. 

Potash. 

Soda. 

Carbonic Acid, 
Water, and Loss. 



p. ct. 

p. ct. 

p. ct. 

p. ct. 

p. ct. 

p. ct. 

p. ct. 

p. ct. 

p. ct. 

Manyard. 

( E. Long- J 

79.38 

8.75 

2.43 


2.57 


4. 

08 

2.79 

Worcester- 

•< meadow, > 

88.89 

5.95 

1.79 

0.41 

0.27 


0. 

86 

1.83 

Kibbie. 

( Mass. ) 

81.38 

9.44 

3 54 

0.11 

0.76 

6.28 



4 49 

Brownstone.. 

Portland, Conn. 

69.94 

13.15 

2.48 

0.70 

3.09 

Trace 

3.30 

5.43 

1.01 

Sandstone.... 

Stony Ft., Mich. 

84.57 

5.90 

6.48 



0.68 

Unde 

ter’d 

1.92 

Quartzite. 

Pipestone, Minn 

84.52 

12.33 

2.12 


6.31 

Trace 

0.11 

0.34 

2.31 

Buff. 

Amherst, Ohio. 

97.00 


1 00 


1 15 


n 

64 

O 91 

Berea. 

Berea, Ohio. 

96.90 


1 68 


0.55 


0. 

55 

n Q9- 

Euclid Bluest. 

Euclid Co., Ohio. 

95.00 

2.50 

1.00 



1.50 

Columbia. 

Columbia, Ohio. 

96.50 




1.00 


0. 

50 

2.00 

Red . 

Laurel Run, Pa. 

94.00 

Trace 

1.90 


1.10 

i .co 



1 92 

Elyria. 

Grafton, Ohio. 

87.66 

1.72 

3.52 


0.17 

0.20 



2.03 

Sandstone... 

Fond du Lac, Mn. 

78.24 

10.88 

3.83 


0.95 

1.60 

1.67 

0 06 

















































MATERIALS EMPLOYED IN THE CONSTRUCTION OF PAVEMENTS. 33 


smooth natural surface, and it has a grain which prevents it from 
becoming slippery; it is not materially affected by freezing and 
thawing; it is strong and not apt to get broken if well laid. 

79. Commercial Names of Sandstone. —The commercial names 
of sandstone are usually obtained from places where it is quarried, 
as, Berea, Grit, Medina, etc. 

80. Table VIII on the opposite page, giving analyses of sandstone 
from a number of localities, will serve to indicate its general com¬ 
position. 

81. The specific gravity, weight, and resistance to crushing of 
various sandstones is given in Table IX. The amount of produc¬ 
tion and value of sandstone for street purposes in the United States 
in 1889 is given in Tables X and XI. 


TABLE IX. 

Specific Gravity, Weight, and Resistance to Crushing of Various 

Sandstones. 


Localities. 

Specific 

Gravity. 

Average Weight, 
pounds per 
cubic foot. 

Resistance to 
Crushing, pounds 
per square inch. 

Potsdam fred). X. Y . 

2.60 

162.28 

42.804 

Medina, X. Y. 

Malden (LluestnncV X. Y . 

2.75 

171.47 

17,725 

Warsaw (Milestone), X. Y. 

Albion X X. 

2.68 

167.10 

13,500 

Craiirlpitli Scotland.. 

2.45 

153 

5,287 

Belleville X J. 

2.56 

159.67 

11,700' 

TC a sot a TVf inn.. 



11,675 

Scncon Ohio. .. 



10,500 

Ttpvpa Ohio . 

2.57 

160.06 

10,250 

Tattle Falls X Y . 



9,850' 

Dorchester, Xew Brunswick — 
Vermilion, Ohio . 

IVTticsillon Ohio . 



9,412 

8,850 

8,750 

Cleveland, Ohio . 

Abroath (pavement), England.. 
TVIr» ronpf.te TVTie.il .. 

2.47 

2 53 

155 

158.17 

7,910 

7,884 

7,450 

Middletown (Portland), Conn... 

f\i nvt!) Amliprst. Ohio . 

2.62 

163.43 

6,950 

6.650 

ftvfprrl tLlnpstoneN N. Y . 

2.71 

168.9 

13,472 

A L U1 v I ( ui uoo to * * oy j • ■*■••• * 

SVinrt rln T.ae Wis . 


6,250 

Hristow V». . . 

2.61 

163 


VnrVcliirp Fn eland . 

2.51 

157 

5,714 



5,000 

TT ill 1 UiiOUUl ^ ) V ii iv/ t . i • 

Tin uorctrnw N V . 



4,350 

Dprhv CrHt, Eneland . 

2.4 

150 

3,100 

Cliootiirp frpdl F.n eland . 

2.15 

133 

2,185 

Vnufl Scotia . 

2.62 

163.50 



_ 













































34 


HIGHWAY CONSTRUCTION. 


TABLE X. 

Production and Value of Sandstone for Street Uses in 1889, by 

States and Territories.* 


States and Territories. 

Cubic Feet. 

Value. 

Value per 
cubic foot. 

Arkansas.. 

27,160 

8,215 

0.30 

California. 

100 

200 

2.00 

Colorado. 

1,926,464 

509,955 

0.26 

Connecticut. 

Idaho... 

40,500 

2,250 

0.06 

Illinois. 

3,200 

50 

0.02 

Iowa. 

8,840 

880 

0.10 

Kansas. 

452,015 

132,188 

0.29 

Kentucky. 

13,900 

1,600 

0.12 

Maryland... 

40,320 

2,045 

0.05 

Massachusetts. 

501,221 

40,471 

0.08 

Michigan. 

2,496 

550 

0.22 

Minnesota. 

51,930 

38,200 

0.74 

Missouri. 

6,533 

2,512 

0.38 

New Mexico. 

10,000 

3,000 

0.30 

New York. 

2.864,366 

459,158 

. 0.16 

Ohio. 

1,603,614 

430,552 

0.27 

Pennsylvania. 

854,907 

175,062 

0.20 

West Virginia. 

Florida, Georgia, Nevada, Rhode 

42,075 

23,274 

0 55 

Island, Vermont. 

13,865 

2,660 

0.19 

Total. 

8,463,506 

$1,832,822 

$0.22 


* 11th U. S. Census. 


TABLE XI. 

Production and Value of “Bluestone” for Street Uses in 1889. 


States. 

Cubic Feet. 

Value. 

Value per 
cubic foot. 

New Jersey. 

15,649 

8,550 

0.55 

New York... 

2,357,724 

475,403 

0.20 

Pennsylvania. 

786,513 

265,959 

0.34 

Total .. 

3,159,886 

$749,912 

$0.24 


82. Limestone.—Limestone is essentially carbonate of lime, but 
it always contains some additional constituent; the more commonly 
occurring impurities or accessory matters are silica in the form of 































































MATERIALS EMPLOYED IN THE CONSTRUCTION OF PAVEMENTS. 35 


quartz, clay, iron, magnesia, etc. And limestones are said to be 
silicious, argillaceous, ferruginous, magnesian, dolomitic, bitumi¬ 
nous, etc., according as they contain one or another of these con¬ 
stituents. Other foreign mineral matter may be found in them^ 
and in such quantity as to give character to the mass. 

In color there is a wide variation, depending upon the impu¬ 
rities; it ranges from the white of the more nearly pure carbonate 
of lime through gray, blue, yellow, red, brown, and to black. 

The texture also varies greatly; it may be coarse or fine. The 
terms coarse-grained and fine-grained are applied when the mass 
resembles sandstone in its granular aggregations. Other terms, 
as saccharoidal (like sugar), oolitic, crinoidal, etc., are also used to 
describe the texture. The state of aggregation of the constituent 
particles varies greatly, and the stone may be hard and compact, 
almost vitreous, or loosely cemented and crumbling with slight 
pressure, like sugar, or, again, like chalk, dull and earthy. 

From this general statement of the range in composition and 
texture, it follows that there is an equally wide variation in hard¬ 
ness, strength, and durability of limestones. Some are hard and 
strong, surpassing in their resistance to crushing force many gran¬ 
ites, and nearly as durable as the best sandstone; others are friable 
and fall to pieces under slight pressure, or they are disintegrated 
rapidly by atmospheric agents. 

83. The limestones are used for flagging and curbing, being 
selected for these purposes on account of accessibility or cheapness. 
For broken-stone roads with light traffic the limestones are emi¬ 
nently suitable; they possess the quality of forming a mortar-like 
detritus which binds the stones together and enables them to wear 
better than a harder material that does not bind. For this purpose 
the most suitable ones are the silicious, magnesian, dolomitic, and 
bituminous. 

84. Tie experience of all cities using paving-blocks of lime¬ 
stone is that it wears unevenly, and in a year or two the blocks are 
shivered and split by the action of frost. 

Table XII shows the specific gravity, weight, and resistance to 
crushing of various limestones. Table XIII shows the production 
and value of limestone for street uses in 1889, by States and Terri¬ 
tories. 



36 


HIGHWAY CONSTRUCTION. 


TABLE XII. 

Specific Gravity, Weight, and Resistance to Crushing of Various. 

Limestones. 


Localities. 

Specific 

Gravity. 

Average 
Weight, , 
pounds per 
cubic foot. 

Resistance to 
Crushing., 
pounds per 
square inch. 

Joliet, Ill.. 



16,900 

Bardstown, Ky. 

2.69 

168 

16,250 

North River, N. Y. 

2.71 

169 

13,425 

Marblehead, Ohio . 

• • • • 


12,600 

Gleiis Falls. N. Y. 

2.70 

169 

11,475 

Marquette, Mich . 

• • • « 

... 

8,050 

Billingsville. Mo . 

• • • • 


7,250 

Caen, France . 

.... 


3,650 

Purheck, England . 

2.6 

162 

9.160 

Anglesea, “ . 

• • • • 

• • • 

7,579 

Blue Lias “ . 

2.467 

154 


TABLE XIII. 

Production and Value of Limestone for Street Uses in 1880, by 

States and Territories.* 



Cubic Feet. 

Value. 

Value per 
cubic foot. 

Alabama. 

98,000 

9,800 

0.10 

Arkansas... 

2,000 

500 

0.25 

California. 

35,000 

1,390 

0.04 

Illinois . 

10,221,392 

505,576 

0.05 

Indiana. 

2,614,862 

316,722 

0.12 

Iowa. 

1,707,931 

53,641 

0.03 

Kansas.... 

771,041 

97,502 

0.13 

Kentucky. 

1,762,711 

86,054 

0.05 

Maryland. 

145,670 

6,750 

0.05 

Michigan. 

485,377 

18,156 

0.04 

Minnesota... 

68,788 

11,778 

0.17 

Missouri. 

11,542,723 

670,351 

0.06 

Nebraska. 

1,926,469 

86,643 

0.04 

New York. 

5,241,262 

197,091 

0.04 

Ohio. 

7,236,981 

183,235 

0.03 

Pennsylvania. 

2,042,804 

72,512 

0.04 

Tennessee . 

14,500 

3,400 

0.23 

Texas... 

67,750 

32,278 

0.48 

Vermont. . 

9,990 

2,098 

0.21 

Virginia. 

7,560 

190 

0.0; t 

Wisconsin. 

488,811 

27,789 

0.06 

Total. 

46,491,622 

$2,383,456 

i 

$0.05 

* 11th U. S. Ceusus. 


85. The material called Ligonier “ Granite,” which is exten¬ 
sively used for paving, etc., is a silicious limestone from localities 






































































MATERIALS EMPLOYED IN THE CONSTRUCTION OF PAVEMENTS. 37 


near Pittsburg, and is said to have a crushing strength of 23,000 
pounds per square inch. 

86. Trap-rock is the common name given to a large group of 
unstratified eruptive or igneous rocks. They are composed of feld¬ 
spar (usually labradorite), augite, hornblende, and some magnetite 
and titanic iron. 

The term trap is derived from trappa, a Swedish word for stair, 
because the rocks of this class frequently occur in large tabular 
masses rising one above the other like steps, as seen on the west 
shore of the Hudson River from Jersey City to Haverstraw. The 
various proportions and states of aggregation of the simple minerals, 
and their differences in external forms, give rise to many varieties 
—such as dolorite, which depends for its hardness upon silica and 
feldspar, and may be either light or dark colored. Basalt is one of 
the most common varieties; it is of a dark green, gray, or black 
color, is composed of augite and feldspar, very compact in texture 
and of considerable hardness, it often contains iron, whence the name 
basalt, an Ethiopian word for iron. Greenstone, another variety, is 
composed of hornblende and feldspar and is of a dark green color. 

The trap-rocks are hard and tough, have no true cleavage, and 
break irregularly; they are difficult to work. But there is much 
variation in the stones of different localities. The rock of the Pali¬ 
sades in New Jersey splits easily into blocks, and has been exten¬ 
sively used for paving in New York, Brooklyn, and Jersey City, 
under the name of “ Belgian block;” but since the introduction of 
granite for this purpose their use has considerably decreased. 

The trap-rocks are exceedingly durable and eminently suitable 
for broken-stone roads, but for paving-blocks they are a failure. 

87. Table XIV shows the crushing resistances, specific gravity, 
and weight of trap-rocks. 

TABLE XIV. 


Crushing Resistance, Specific Gravity, and Weight of Trap-rocks. 


Locality. 

Resistance to 
Crushing, pounds 
per square inch. 

Specific 

Gravity. 

Weight of one 
cubic foot, 
pounds. 

Staten Island, N. Y. 

22.250 

2.86 

178 8 

Jersey City Heights, N. J.. 

Palisades, N. J. 

20,750 to 22.250 
19,700 

8.03 

189.5 






















38 


HIGHWAY CONSTRUCTION. 


88. Bitumen, Asphaltum, Asphalt.— Bitumen is the name used 
to denote a group of mineral substances, composed of different hy¬ 
drocarbons, found widely diffused throughout the world in a variety 
of forms which grade from thin volatile liquids to thick semi-fluids, 
and solids, sometimes in a free or pure state, but more frequently 
intermixed with or saturating different kinds of inorganic or organic, 
matter. 

88a. To designate the condition under which bitumen is found 
different names are employed; thus the liquid varieties are known 
as naphtha and petroleum, the semi-fluid or viscous as maltha or 
mineral tar, and the solid or compact as asphaltum or asphalt . 

89. Th ree distinct varieties of asphaltum are recognized, 
namely, the earth//, the elastic, and the hard or compact. 

89a. The earthy variety, represented by the chapopota of 
Mexico, Colombia, and other parts of South America, has a brown¬ 
ish-black dull color, an earthy uneven fracture, when freshly ex¬ 
cavated a strong though not unpleasant earthy odor, is soft enough 
to take an impression of the nail, hardens slightly on exposure to 
the atmosphere, and burns with a clear brisk flame, emitting a. 
powerful odor, and depositing much soot. 

89b. Elastic asphaltum is of various shades of brown; is soft, 
flexible, and elastic; it has an odor strongly bituminous, and is of 
about the density of water; it burns with a clear flame and much 
smoke. Like caoutchouc, it takes up pencil marks, and on this 
account is called mineral cauotchouc; it has been found only at 
three places: in the fissures of a slaty clay at Castleton, England; 
at Montrelais, France; and in Massachusetts. 

89c. Hard or compact asphaltum is the most useful variety; it 
forms large deposits in many parts of the world, and is of various, 
degrees of quality, according to its age and the impurit'ies mixed 
with it; when nearly pure its ordinary characteristics are as follows: 
Color brownish black and black; lustre resinous or coal-like; 
opaque. At temperatures below 100° F. it is brittle and breaks 
with a conchoidal fracture. Melts ordinarily at 190° F. to 195° F., 
and is liquid at about 212° F. At 212° F. it has a peculiar but 
agreeable aromatic odor, somewhat resembling, but still very differ¬ 
ent from, that of coal tar; at ordinary temperatures the odor is 
scarcely perceptible, but when rubbed it is quite strong. It kindles 



MATERIALS EMPLOYED IN THE CONSTRUCTION OF PAVEMENTS. 89 


readily and burns brightly with a thick smoke. Distilled by itself 
it yields a bituminous oil of a yellow color (consisting of hydrocar¬ 
bons mixed with oxidized matter), water, some combustible gases, 
and sometimes traces of ammonia. 

After combustion it leaves about one third of its weight of char- 
coal and ashes containing silica, alumina, oxide of iron, sometimes 
oxide of manganese, lime, and other inorganic and organic matter. 
Its composition and hardness are variable. 

Specific Gravity .—Pure bitumen has a density less than water; 
but in consequence of the impurities mixed with it the specific 
gravity of asphaltum varies from 1.0 te 1.7. Solubility: It is 
insoluble in water, partly or wholly soluble in chloroform and 
disulphide of carbon, partly or wholly in oil of turpentine and 
petroleum ether, and commonly partly in alcohol. 

90. By different solvents asphaltum may be decomposed into 
three distinct though complex substances which have been named 
by Boussingault and other chemists who have investigated it 
petrolene, asphaltene, and retine. Nothing definite is known 
concerning these compounds or how their variable proportions and 
composition affect the quality of an asphaltum. In the past they 
have received but little attention from chemists, due probably to 
the limited use of asphaltum; but now, in view of its large and 
increasing employment for paving and other industrial purposes, 
their investigation offers a wide and undoubtedly profitable field 
for chemical research. 

90a. The characteristics of these compounds, so far as known, 
are generally as follows: 

Petrolene is the compound which is considered to give the vis¬ 
cous or adhesive quality. It may be described as that portion of 
the bitumen which is soluble in petroleum ether. It is lighter than 
water, very combustible, and has a high boiling-point, pale yellow 
color, and peculiar odor. On evaporating off the ether it remains, 
as a resin with a brownish-black color, which dissolves readily in 
the volatile oils. Its composition is carbon, hydrogen, and sulphur. 
The amount present in an asphaltum is variable, ranging from 3 to- 
70 per cent of the weight of the asphaltum. 

Asphaltene is the compound which gives the hardness to as¬ 
phaltum. It contains the elements of petrolene, together with a 




40 


HIGHWAY CONSTRUCTION. 


quantity of oxygen, and probably arises from the oxidation of that 
compound. It is that portion of the bitumen which is insoluble 
in ether. It is dissolved out by carbon disulphide, chloroform, 
benzene, etc. Its color is a brilliant black; density greater than 
water. It burns like resins in general, leaving a very abundant 
coke. Like petrolene, it is composed of carbon, hydrogen, and 
oxygen, and the amount present in an asphaltum is as variable— * 
ranging from 1 to about 60 per cent. 

Retine is dissolved out by alcohol (anhydrous) from that por¬ 
tion of the asphaltum which is unaffected by the solvents above 
mentioned. It is a yellow resin composed of carbon, hydrogen, 
and sulphur. What effect this compound has upon asphaltum is 
unknown. Some authorities claim that its presence is injurious. 

91. Origin of Bitumen.—The origin of bitumen is unknown. It 
is supposed to be the ultimate product resulting from the destruc¬ 
tion under certain conditions of the organized remains of animals 
and vegetables, producing (1) naphtha, (2) petroleum, (3) maltha 
or mineral tar, (4) asphaltum. The whole of these substances 
merge into each other by insensible degrees, so that it is impossible 
to say at what point maltha ends and asphaltum begins. Naphtha , 
the first of the series, is in some localities found flowing out of the 
earth as a clear, limpid, and colorless liquid; as such it is a mix¬ 
ture of hydrocarbons, some of which are very volatile and evapo¬ 
rate on exposure. It takes up oxygen from the air, becomes brown 
and thick, and in this condition it is called petroleum. 

91a. The hardening of the bituminous fluids which have oozed 
out or been exposed by other causes upon the surface of the earth 
seems, in most cases at least, to have resulted from the loss of the 
vaporizable portions, and also from a process of oxidation which 
consists, first, in a loss of hydrogen, and finally in the oxygenation 
or evaporation of the more volatile portions, which gradually trans¬ 
forms them into mineral tar or maltha, and, still later, into solid 
glossy asphaltum, of which gilsonite , wurtzilite, uintahite, etc., 
are examples. 

92. Occurrence and Distribution of Asphaltum.—Deposits of 
asphaltum are found widely diffused throughout the world, and at 
various altitudes ranging from below sea-level to thousands of feet 
above. It is, however, seldom found among the primitive or older 



.MATERIALS EMPLOYED IN THE CONSTRUCTION OF PAVEMENTS. 41 


rock formations, but seems to belong exclusively to the secondary 
and tertiary formations. Intermixed with the argillaceous stratas, 
it forms extensive beds or lakelike deposits on both continents, the 
most remarkable of which are those situated in the West Indies 
and South America. The most notable of these are the so-called 
pitch lakes on the island of Trinidad, and at Bermudez, Venezuela. 

92a. Saturating the calcareous and sandstone formations, it 
forms large subterraneous deposits in Europe and the United 
States. The calcareous varieties occur more extensively in Europe 
than in America, and are the source of the material employed 
there for street-paving under the name of aspJialte . The sand¬ 
stone class is found extensively in the Western and Southwestern 
States, especially in California, Texas, Kentucky, and the Indian 
Territory. 

92b. In a free or nearly pure state it is found in veins and 
seams in the primitive rock and volcanic formations. This class of 
deposit is rare and the amount of asphaltum is generally insignifi¬ 
cant. A notable exception, however, are the deposits of Utah, etc. 
The mines from which gilsonite, wurtzilite, uintahite are produced 
are said to be very extensive, and the material is very nearly pure. 
Similar deposits are found in Mexico, Cuba, and various parts of 
South America. 

92c. In many localities beds of shale, sand, and cretaceous lime¬ 
stone are found saturated with maltha, from which the bitumen is 
extracted by boiling or macerating with water. 

92d. From the variety of the deposits and their manner of 
occurrence it seems that asphaltum belongs to no particular era 
or age. Moreover, the asphaltum obtained from these different 
sources is not uniform either in character, appearance, hardness, 
or chemical composition. The ultimate composition of specimens 
from several localities is given in Table XIVtf. 

93. Nomenclature.—As indicated above, the varieties of bitumen 
and asphaltum areas numerous as the localities producing them; 
hence there is a great variety of names used to designate the 
same substance which is oftentimes misleading, if not confusing. 
As an illustration of this variety the following may be mentioned: 
native pitch, mineral pitch, glance pitch, grahamite, albertite, 
piauzite, elaterite, gilsonite, wurtzilite, uintahite, turrellite. 



42 


HIGHWAY CONSTRUCTION. 


TABLE XI Va. 
Composition op Asphaltum. 


Locality. 

Carbon. 

Hydrogen. 

Oxygen. 

Nitrogen. 

Sulphur. 

Ash. 


( 80.32 

6.30 

0.56 


2.49 


Trinidad, W. I. .. 

1 t0 

to 

to 

to 

to 



( 85.89 

11.06 

1.40 

0.50 

11.48 


Cuba, “ ... 

82.34 

9.10 

6.25 

1.91 


0.40 

Caxatambo, Peru . 

88.66 

9.69 

1. 

65 



N. S. (Albertite). . 

86.04 

8.96 

1.97 

2.93 

trace 

0.10 

W.Va (Grahamite) 

76.45 

7.83 

13.14 



2.26 

Auvergne, Frauce 

77.64 

7.86 

8.35 

1.02 


5.13 

Oklahoma, I. T.. . 

\ 55.00 

10.21 

7.14 

2.74 


24.91 


l 





and silicates 

Mexico. 

80.34 

10.09 

9.57 




Utah (Gilsonite)... 

80.88 

9.76 

6.05 

3.30 


0.01 


93a. Sometimes the name of the locality where it is found is 
used as a prefix and is thus useful to indicate the source. Such 
names are Dead Sea bitumen, Egyptian asphalt, Cuban, Trinidad, 
Bermuda, Californian, Kentucky, etc. 

93b. The name asjihalte has been adopted by the French 
to designate the material obtained from their bituminous limestone 
deposits, and is now generally employed throughout Europe to 
denote both the carbonate of lime impregnated with asphaltum 
and the pavement made from that material. 

93c. The name Uthocarbo7i has been recently adopted to 
designate a cretaceous limestone saturated with bitumen found in 
Texas. 

93d. Some authorities apply the terms asphaltum, asphalt, and 
liquid asphalt to the semi-fluid and viscous bituminous substance 
or maltha, which by heat may be transformed into asphaltum. 
This application seems to be erroneous, because asphaltum techni¬ 
cally means bitumen in the solid form. Others use the same terms 
r to designate the entire mixture of bitumen, mineral and organic 
matter, while others apply them to denote the purified material. 

94. The names which seem to be the most used in the United 
States and which are at the same time descriptive of the various 
classes are as follows: 































MATERIALS EMPLOYED IN THE CONSTRUCTION OF PAVEMENTS. 43 


Crude asphaltum or crude asphalt is applied to all mixtures 
of bitumen, clay, sand, etc.; e.g., crude Trinidad asphalt. 

Refined asphaltum or asphalt is used to denote the asphaltum 
after it has been wholly or partly freed from the combined organic 
and inorganic matters. 

The limestone rocks impregnated with bitumen are called 
bituminous or asphaltic limestones. The term rock asphalt is 
also applied to the same material, the name of the source being also 
used, as “Italian rock asphalt,” “Val de Travers rock asphalt,” 
etc. 

The sandstones containing bitumen are known as bituminous or 
asphaltic sandstones , the name of the source being also mentioned. 

The semi-fluid bitumen is designated by the names maltha 
and mineral tar. 

The term asphalt is also frequently but erroneously applied 
to various preparations in which the cementing material is coal tar 
or the residue of oil-refineries, etc.—substances which are entirely 
dissimilar to asphaltum, though apparently possessing some of its 
characteristics. 

The term bitumen is employed to designate the truly bitumi¬ 
nous portion of the asphaltum and its compounds. 

95. Refined Asphaltum is asphaltum freed from the combined 
water and accompanying inorganic and organic matter. By com¬ 
paratively simple operations the several varieties of asphaltum may 
be reduced to an equal state of purity. 

95a. The argillaceous varieties, such as Trinidad, Bermudez, 
etc., are purified in iron vessels by the application of heat either 
directly from fire or indirectly by steam, the temperature em¬ 
ployed ranges from 212° F. to 350° F. During the application of 
the heat, the asphaltum is liquefied the, combined water is evapor¬ 
ated, the organic matters rise to the surface and are skimmed off, 
and the inorganic settle to the bottom of the vessel; when the 
liberation of the impurities -is completed, the liquid asphaltum is 
drawn off into barrels and constitutes the refined asphaltum of 
commerce. 

95b. The calcareous and silicious varieties are purified by boil¬ 
ing or macerating them with hot water, according to the freedom 
with which they part with the intermixed impurities. During the 




44 


HIGHWAY CONSTRUCTIONS 


action of the water the sand and other ingredients fall to the bottom 
of the vessel, and the bitumen rises to the surface or forms clots on 
the sides of the boiler, whence it is skimmed off and thrown into 
another boiler, where it is boiled for some time, during which the 
water and more volatile oils are evaporated, and the mineral matters 
still retained fall to the bottom, leaving the bitumen in the form of 
a thick viscid substance, in which state it is used in several of the 
arts. By continuing the boiling for a considerable time or by 
increasing the temperature to about 250° F. the volatile portions 
are driven off and the viscid bitumen is brought to a condition 
which upon cooling causes it to become solid. 

95c. The operation of refining or purifying, while exceedingly 
simple, requires to be performed with much care, for the reason that 
if the asphaltum is melted at too high a temperature it will be 
burned or coked, or if the heating is prolonged at a low tempera¬ 
ture the result will be practically the same. In either case the 
petrolene is converted into asphaltene. 

96. Asphaltic Cement.—Asphaltum in a refined or pure state 
is valueless as a cementing medium, owing to its hardness, brittle¬ 
ness, and lack of cementitious properties; therefore it is necessary 
to add some substance which will impart to it the required plastic, 
adhesive, and tenacious qualities. This substance must be one that 
will partially dissolve the asphaltene and form a chemical union by 
solution instead of a mechanical mixture. The duty which it has 
to perform is an important and peculiar one: if it is a perfect sol¬ 
vent of the constituents of the bitumen, the adhesive qualities will 
be destroyed ; if it is an imperfect one, the asphaltum will retain its 
brittleness. 

96a. The requirements of a suitable flux arc that it shall be a 
fluid containing no substances volatile under 300° F., and shall 
possess the power to dissolve the asphaltum without destroying or 
lessening its adhesive properties. 

96b. The materials employed to give the required qualities to 
the hard asphaltum are called the “flux,” and those in general 
use are crude or specially prepared residuum oil obtained from 
the distillation of petroleum, and crude or refined maltha. 

The process of adding the flux is called “ oiling ” or “ temper¬ 
ing,” and is conducted as follows : The refined asphaltum is 





MATERIALS EMPLOYED IX THE CONSTRUCTION OF PAVEMENTS. 45 


melted and the temperature raised to about 300° F.; the oil previ¬ 
ously heated is then pumped or in other ways added to the 
asphaltum, in the proportion of 10 to 20 pounds of oil to 100 
pounds of refined asphaltum—the proportion of the oil is varied 
between the limits stated according to its quality, the hardness of 
the asphaltum, and the purpose for which the cement is to be em¬ 
ployed. The mixture of residuum oil and asphaltum is agitated 
either by mechanical means or by a blast of air for several hours 
or until the material has acquired the desired properties. The 
agitation must be performed with great thoroughness to secure a 
uniform mixture, and must be continued whenever the material 
is in a melted condition, as a certain amount of separation takes 
place when the melted cement stands at rest. It is therefore 
customary to agitate it constantly when in use as well as during its 
preparation. 

96c. The process of “ tempering ” when maltha is used as 
the flux is practically the same as outlined above, with the excep¬ 
tion that the mixing is performed at a lower temperature and 
entirely by mechanical means, and a separation of the ingredients 
seldom occurs when the cement is standing at rest. 

96d. The maltha from many localities is to be had in the 
market; it is sold for fluxing purposes under various trade names, 
among which may be named "Alcatraz” liquid asphaltum, 
“ Standard ” liquid asphalt, "Utah ” liquid asphalt, etc.; also arti¬ 
ficial fluxing materials which are offered as substitutes for oil and 
maltha, such as the “ Pittsburg asphaltic flux,” etc. The analyses 


of some of these fluxing agents are as follows : 

“Alcatraz” Liquid Asphalt. 

Specific gravity .. L05 

Bitumen soluble in carbon disulphide. 98.70 per cent. 

Bitumen soluble in petroleum naphtha..89.17 

Mineral matter. . 1-30 

Organic non-bituminous matter. trace. 

“ Utah” Liquid Asphalt (Crude ) 

Specific gravity. 0.9068 

Bitumen soluble in carbon disulphide. 76.15 per cent. 

Bitumen soluble in ether.64.90 

Mineral matter . 3 40 

Organic non-bituminous matter.20.45 

Loss at 100°C. 24. <2 
















46 


HIGHWAY CONSTRUCTION. 


“Pittsburg” Asphaltic Flux. 


Moisture. 0.05 per cent. 

Volatile oil 212° F. to 312° F. 1.60“ “ 

Volatile oil about 312’ F. 89.19 “ “ 

Fixed carbon. 8.48 “ 

Ash. 0.68 “ “ 

Bitumen soluble in carbon disulphide... 99.32 “ 

Bitumen soluble in ether. 65.00 “ 


97. The enduring qualities of an asphaltic cement depend 
upon (1) the character of the fluxing agent, (2) the temperature 
at which the asphaltum has been refined and the temperature at 
which the flux is added, (3) the degree of incorporation of the flux 
with the asphaltum, that is whether the union is a chemical or 
mechanical one. 

97a. The diversity found in the durability of pavements made 
from cement in which the flux is residuum of petroleum is con¬ 
sidered by many authorities to be due primarily to the variable 
character of the residuum. This material is a thick heavy oil 
varying considerably in composition, according to the source of the 
petroleum and method of distillation; its base is paraffine —a sub¬ 
stance so different from asphaltum that when the two are brought 
together the result is a mixture partly mechanical and partly 
chemical, and, being of different specific gravities, they partly sepa¬ 
rate when allowed to stand for any considerable period without 
stirring. 

97b. During the early days of the manufacture of asphaltic 
cement, for paving purposes, from Trinidad asphaltum and 
residuum oil, the oil as it came from the refineries was poured 
directly into the liquid asphaltum without any investigation as to 
its quality. The results produced by this method in cements 
nominally prepared in exactly the same way were very variable 
and oftentimes unsatisfactory. With the increased demand for 
asphaltic cement many improvements both in the method of add¬ 
ing the oil and in its quality have been made. The oil is now 
subjected to careful examination to ascertain : 

1. Specific gravity. 

2. Flash-point. 

3. Percentage volatile in a given time at 400° F. 










MATERIALS EMPLOYED IN THE CONSTRUCTION OF PAVEMENTS. 47 


4. Susceptibility to changes in temperature as revealed by 
changes in viscosity. 

5. Presence of crystals of paraffine. 

97c. The demand for heavy petroleum oil .or residuum for use 
in the manufacture of cement for paving purposes has become so 
extensive that the oil-refining companies find it profitable to pro¬ 
duce an oil that shall be nearly uniform in character. In pre¬ 
paring this oil the object aimed at is (1) the removal of the hard 
paraffines, which are very susceptible to changes of temperature, 
becoming soft under the summer sun and brittle at or below the 
freezing-point; their presence impart similar properties to the 
asphalt cement; (2) to remove the lighter and more volatile 
oils; care in their removal must be exercised: if too large a per¬ 
centage is removed, the oil becomes heavy and thick, and too large 
a proportion is required to make a cement of suitable consistency— 
therefore there is a limit to the amount that can be removed. 

97d. The specifications of Washington, D. C., provide that the 
heavy petroleum oil used in the manufacture of asphalt cement 
shall have the following characteristics: 

* 

It shall be a petroleum from which the lighter oils have been 
removed by distillation without cracking. 

Specific gravity Baume 17° to 21°. Flash-point not less than 
300° F. Distillate at 400° F. for ten hours less than 10 per cent. 

Shall not cease to flow above G0° F. Shall not require more 
than 21 pounds of oil for each 100 pounds of refined asphalt to 
produce the specific quality of cement. 

The flash-point shall be taken in a New York State closed oil- 
tester. The distillate shall be made with about 90 grams of oil in 
a small glass retort provided with a thermometer and packed en¬ 
tirely in asbestos. 

The flowing-point shall be determined by cooling 100 cc. of oil 
in a small bottle and noting the temperature at which it flows 
readily from one end of the bottle to the other. 

98. Authorities differ as to the relative merits of residuum oil 
and maltha as fluxes for asphaltum. Some claim that they are 
unsuitable on account of the volatile oils they contain, which on 
evaporating leave the cement in a porous or spongelike condition, 
which readily absorbs water, and is thus subject to the destroying 



48 


HIGHWAY CONSTRUCTION. 


action of frost. Others hold that if the oil or maltha is heated 
sufficiently to drive off the volatile oils they are deprived of their 
solvent power and are converted into substances so similar to as- 
phaltum that their, addition renders it more brittle. 

98a. The writer, from his observations, considers that a more 
enduring cement can be obtained by adding asphaltum to maltha 
and allowing it to dissolve therein at a temperature of 212° to 220° 
F., or by submitting maltha to a process of distillation in which 
the temperature is carefully regulated. Under such a process 
bitumen of any consistency from plastic to hard can be produced. 
Either of these methods would be more satisfactory and more 
under control than the present one of transforming a compara¬ 
tively hard and brittle substance into a soft and plastic one. 

98b. An examination of the bituminous limestones and sand¬ 
stones shows them to be cemented together, not by hard bitumen, 
but by the softer varieties; and where these formations have been 
exposed to the destroying action of the elements they show no sign 
of disintegration, but are solid and impervious. 

98c. Some of the most enduring constructions of antiquity, 
which have withstood the ravages of time for upwards of 3000 
years, are cemented with bitumen. The bitumen which the an¬ 
cients used was not the hard brittle variety we employ, but the 
soft plastic maltha, used in its natural condition as it oozed out of 
the springs. 

99. Asphaltic Paving Materials.—All asphaltic or bituminous 
pavements are composed of two essential parts, namely, the ce¬ 
menting material (matrix) and the resisting material (aggregate). 
Each has a distinct function to perform: the first furnishes and 
preserves the coherency of the mass; the second resists the wear 
of the traffic. 

99a. Two classes of asphaltic paving compounds are in use, 
namely, natural and artificial. The natural variety is composed 
of either limestone or sandstone naturally cemented by bitumen. 
To this class belong the bituminous limestones of Europe, Texas, 
Utah, etc., and the bituminous sandstones of California, Kentucky, 
Texas, Indian Territory, etc. The artificial consists of mixtures of 
asphaltic cement manufactured, as described in Art. 96, with sand 
and stone-dust. To this class belong the pavements made from 



MATERIALS EMPLOYED IN THE CONSTRUCTION OF PAVEMENTS. 49 


Trinidad, Bermudez, Cuban, and similar asphalturns. For the 
artificial variety most of the hard bitumens are, when properly 
prepared, equally suitable. For the aggregate the most suitable 
materials are stone-dust from the harder rocks, such as granite, 
trap, etc., and sharp angular sand. These materials should be 
entirely free from loam and vegetable impurities. The strength 
and enduring qualities of the mixture will depend upon the 
quality, strength, and proportion of each ingredient, as well as 
upon the cohesion of the matrix and its adhesion to the aggregate. 

99b. Bituminous Limestone consists of carbonate of lime natu¬ 
rally cemented with bitumen in proportions varying from 80 to 93 
per cent of carbonate of lime and from 7 to 20 per cent of bitumen. 
Its color when freshly broken is a dark (almost black) chocolate- 
brown, the darker color being due to a larger percentage of bitu¬ 
men. At a temperature of from 55° to 70° F. the material is hard 
and sonorous and breaks easily with an irregular fracture; at tem¬ 
peratures between 70° and 140° F. it softens, passing with the rise 
in temperature through various degrees of plasticity, until, at be¬ 
tween 140° and 1G0° F., it begins to crumble, at 212° F. it com¬ 
mences to melt, and at 280° F. it is completely disintegrated. Its 
specific gravity is about 2.235. 

99c. Bituminous limestone is the material employed for paving 
purposes throughout Europe. It is obtained principally from de¬ 
posits at Val-de-Travers, canton of Neufchatel, Switzerland; at 
Seyssel, in the department of Ain, France; at Ragusa, Sicily; at 
Limmer, near Hanover; and at Vorwohle, Germany. 

99d. The constituents of the more important of these deposits 
are given in Table XV. 

99e. Bituminous limestone is found in several parts of the 
United States. Two of these deposits are at present being worked, 
one in Texas, the material from which is called “ lithocarbon,” 
and one on the Wasatch Indian Reservation. These deposits con¬ 
tain from 10 to 30 per cent of bitumen. 

99f. The bituminous limestones which contain about 10 per 
cent of bitumen are used for paving in their natural condition, 
being simply reduced to powder, heated until thoroughly softened, 
then spread while hot upon the foundation and tamped and rammed 
until compacted. 




50 


HIGHWAY CONSTRUCTION. 


TABLE XV. 

Analysis of European Bituminous Rocks.* 


Constituents. 

Val 

de 

Travers. 

Seyssel. 

l 

Lobsan. 

Sicil¬ 

ian. 

Mae- 

stu. 

Forens. 


Per 

Per 

Per 

Per 

Per 

Per 


cent. 

cent. 

cent. 

cent. 

cent. 

cent. 

Water and matter vol. at 212° F.f 

0.50 

1.90 

3.40 

0.80 

0.40 

0.25 

Bitumen. 

10.10 

8.00 

11.90:}: 

8.85 

8.80 

2.25 

Carbonate of lime. 

87.95 

89.55 

69.00 

87.50 

9.15 

97.00 

Silicious sand. 



3.05 

0.60 

57.40 


Alumiuum and peroxide of iron 

0.25 

0.15 

5.70§ 

0.90 

4.35 

0.15 

Sulphur. 



5.00 




Carbonate of magnesia. 

0.30 

0.10 

0.30 

0.95 

8.10 

0.20 

Different materials insol. in acids 

0.45 

0.10 



11.35 

0.05 

Loss. 

0.45 

0.20 

1.65 

0.40 

0.45 

0.10 


100.00 

100.00 

100.00 

100.00 

100.00 

100.00 


* Laboratoire de 1’fCcole des Pouts et Chaussees. M. Leon Malo. 

f The water given above depends on the dryness of the sample at the time 
of analysis, the figures not being of importance in the result. 

\ This quantity appeared to contain a certain proportion of oil, which was 
mixed with the bitumen and was not exactly determined. 

§ This comprises 4.45 per cent of iron combined with sulphur. 

99g. Bituminous Sandstones are composed of sandstone rock 
impregnated with bitumen in amounts varying from a trace to 70 
per cent. They are found both in Europe and America. In Europe 
they are chiefly used for the production of pure bitumen, which is 
extracted by boiling or macerating them with water. In the Uni¬ 
ted States extensive deposits are found in the Western States, and 
since 1880 they have been gradually coming into use as a paving 
material, and now upwards of a hundred and fifty miles of streets 
in Western cities are paved with them. They are prepared for use 
as a paving material by crushing to powder, which is heated to 
about 250° E. or until it becomes plastic, then spread upon the 
street and compressed by rolling; sometimes sand or gravel is 
added, and it is stated that a mixture of about 80 per cent of gravel 
makes a durable pavement. 

100. Trinidad Asphaltum.—The deposits of asphaltum in the 
island of Trinidad, W. I., have been the main source of supply for 


































MATERIALS EMPLOYED IN THE CONSTRUCTION OF PAVEMENTS. 51 

/ 

the asphaltum used in street-paving in the United States. Three 
kinds are found there, which have been named, according to 
the source, lake pitch, land or overflow pitch, and iron pitch, 
The first and most valuable kind is obtained from the so-called 
Pitch-lake; this lake or deposit is situated about 2 miles from 
the seashore of the island at an elevation of 138 feet, and has an 
area of about 115 acres and is of unknown depth. It is quite cir¬ 
cular in shape, and is supposed to occupy the crater of an extinct 
mud volcano. The surface is not flat and even, but is formed of 
irregular oval-shaped domes, resembling large mushrooms, separated 
by narrow and shallow channels and pools of water; with the 
exception of a small space in the centre the surface is sufficiently 
hard to support the weight of animals and loaded carts. The 
small space in the centre is called the “ boiling spring.” Here soft 
pitch still wells up, but soon becomes hard. The asphaltum is 
easily excavated with picks, and in the early days of the industry 
was loaded into two-wheeled carts, hauled by mules to the shore, 
and there dumped into piles, from which it was carried in baskets 
by coolies wading through the surf to lighters and from the lighters 
loaded into sailing vessels. Recently the concessionaires of the lake 
have built a tramway and pier by which the material is easily con¬ 
veyed and quickly loaded into the vessels lying at the pier. 

100a. The term land or overflow pitch is applied to the 
deposits of asphaltum found outside of the lake. These deposits 
form extensive beds of variable thickness, and are covered with 
from a few to several feet of earth; they are considered by some 
authorities to be formed from pitch which has overflowed from the 
lake, by others to be of entirely different origin. The name cheese 
pitch is given to such portions of the land pitch as more nearly 
resemble that obtained from the lake. 

100b. The term iron pitch is used to designate large and isolated 
masses of extremely hard asphaltum found both within and with¬ 
out the borders of the lake. It is supposed to have been formed 
by the action of heat caused by forest fires which, sweeping over 
the softer pitch, removed its more volatile constituents. 

100c. The name epuree is given to asphaltum refined on the 
island of Trinidad. The process is conducted in a very crude 
manner in large, open, cast iron sugar boilers. 



52 HIGHWAY CONSTRUCTION. 

100d. The Characteristics of Crude Trinidad Asphaltum, both 
lake and land are as follows: It is composed of bitumen mixed 
with fine sand, clay, and vegetable matter. Its specific gravity 
varies according to the impurities present, but is usually about 
1.28. Its color when freshly excavated is a brown, which changes 
to black on exposure to the atmosphere. IVhen freshly broken, 
it emits the usual bituminous odor. It is porous, containing 
gas-cavities, and in consistency it resembles cheese. If left long 
enough in the sun, the surface will soften and melt and will finally 
flow into a more or less compact mass. The average composition 
of both the land and lake varieties is shown by the following 
analyses: 

TABLE XVa. 

Average Composition of Trinidad Asphaltum. 


Constituents. 

Lake. 

Land. 

Hard. 

Soft. 

Water. 

Per cent. 

27.85 

26.88 

7.63 

38.14 

Per cent. 

34.10 

25.05 

6.35 

34.50 

Per cent. 

26.62 

27.57 

8.05 

37.76 

Inorganic matter. 

Organic non-bituminous matter... 
Bitumen. . 

When the analyses are calculated 
to a basis of dry substances, 
the composition is inorganic 
matter... 

100.00 

100.00 

100.00 

36.56 

10.57 
52.87 

38.00 

9.64 

52.36 

37.74 

10.68 

51.58 

Organic matter not bitumen. 

Bitumen. 

The substances volatilize, in 10 

hours at 400° F. 

‘ “ soften at. 

100.00 

100.00 

100.00 

3.66 
190° F. 
200° F. 

12.24 
170° F. 
185° F. 

0.86 to 1.37 
200° to 250° F. 
210° tc 328° F. 

“ “ flow at. 



lOOe. Refined Trinidad Asphatum. —The crude asphaltum is 
refined or purified by melting it in iron kettles or stills by the ap¬ 
plication of indirect heat. In the earlier refineries upright cylin- 










































MATERIALS EMPLOYED IN THE CONSTRUCTION OF PAVEMENTS. 53 


drical kettles holding about ten tons were used; the heat was 
obtained from a coal fire, the kettles being protected from its 
direct action by a brick arch. In this form of still the refining 
process occupied from one hundred and twenty to one hundred 
and forty hours, and, as the plant became deteriorated, much 
longer; sediment collected on the bottom, causing much waste of 
fuel, coking of the asphaltum, and the burning out of the still 
itself. In consequence of these defects their use is practically 
abandoned and in their place horizontal boilers have been adopted. 
In their most approved form these boilers or stills consist of a 
boiler about twenty feet long and ten feet in diameter furnished 
with two longitudinal flues eighteen inches in diameter placed four 
feet from the bottom and four feet between centres. These stills 
are placed in brickwork surrounded with loam to prevent radia¬ 
tion, and are provided with flues so arranged that the direct heat 
from the fire passes first along one side, then back along the other, 
repeating this at a higher level, then through one flue in the still 
and back through the other, and finally under the bottom. In 
this way overheating on the bottom is prevented and better results 
are obtained in evaporating the water from the upper layers of 
crude material. These stills hold about thirty tons of crude ma¬ 
terial, and the time of refining is much reduced. After some years 
practice with the above-described method agitation of the asphal¬ 
tum with a current of air during the refining process was intro¬ 
duced, with the object of further reducing the time required 
and the possibility of injury to the asphaltum. 

Recently a departure has been made from this last-described 
method; it consists in the use of steam-heat in place of coal-fire 
heat. The objects aimed at are a reduction in time and prevention 
of the injury by coking or burning of the asphaltum, which fre¬ 
quently occurred when refining with direct heat. In this later 
process instead of large cylindrical boilers or stills smaller rectangu¬ 
lar kettles are used, holding about twenty-five tons ; these are fur¬ 
nished with gangs of pipe for the circulation of steam at a press¬ 
ure of about 100 pounds per square inch; agitation is produced 
by jets of dry steam or air. By this method a charge is refined in 
about twelve hours and the product is very uniform in quality. 

lOOf. Irrespective of the method adopted for heating, the proc- 




54 


HIGHWAY CONSTRUCTION. 


ess of refining proceeds as follows : During the heating the water 
and lighter oils are evaporated, the asphaltum is liquefied, the 
vegetable matter rises to the surface and is skimmed off, the 
earthy and silicious matters settle to the bottom, and the liquid 
asphaltum is drawn off into old cement- or flour-barrels. 

lOOg. When the asphaltum is refined without agitation, the 
residue remaining in the still forms a considerable percentage of 
the crude material, frequently amounting to 12 per cent, and it 
was at one time considered that the greater the amount of this 
residue the better the quality of the refined asphaltum ; but since 
agitation has been adopted the greater part of the earthy and 
silicious matters are retained in suspension and it has come to 
be considered just as desirable for a part of the surface mixture 
as the sand which is subsequently added. The refined asphaltum, 
if for local use, is generally converted into cement in the same 
still in which it was refined. 

lOOh. In the earlier part of the refining process the water con¬ 
tained in the crude material is liberated and forms in pools on the 
surface ; this water is of a distinct saline and thermal character, 
containing a large amount of salts in solution, which probably 
explains the efflorescence seen upon the crude asphaltum and which 
is frequently attributed to sea salt. 

lOOi. The principal salts in solution are, in the order of their 
amount, sodic chloride and sulphate, ammonic, potassic, and fer¬ 
rous sulphates, borates, iodides, etc. 

100j. The distillate from the stills is strongly acid, and free 
hydrochloric, sulphuric, and hydrosulphuric acids and other sul¬ 
phur compounds have been determined in it. 

100k. The steam which is formed in the refining of the crude 
asphaltum at first contains much hydrogen sulphide, which blackens 
all the white-lead paint in the vicinity of the refinery. This, under 
favorable conditions of heat and evaporation, at times changes to 
sulphurous anhydride, which again bleaches out the white paint. 
The condensed steam shows a strongly acid reaction. In the pres¬ 
ence of one another the hydrocarbons and the thermal water at 
high temperature evidently produce complicated reactions. 

1001. The residue from the bottom of the still consists of some 
clay mixed with silica in the form of minute fragments of quartz 



MATERIALS EMPLOYED IN THE CONSTRUCTION OF PAVEMENTS. 55 


and some of the salts contained in the water. An analysis showed 


it to consist of: 

Clay, silica, aud silicates insoluble in acid. 87.67 p.c. 

Soluble salts, alumina, iron, lime, etc. 12.33 p.c. 


100.00 p. c. 

Of the insoluble portion about 95 per cent is silica, and fre¬ 
quently the lime is absent. 

100m. The organic matter not bituminous posseses no dis¬ 
tinctive characteristics; it occurs as an impalpable powder wnthout 
any signs of organization. 

lOOn. The Characteristics of Refined Trinidad Asphaltum are 
as follows: 


Average Composition op Refine© Trinidad Asphaltum. 



Lake. 

Land. 

Specific gravity at 77° F... .. 

1.38 

Per cent. 

56.29 

8.05 

35.66 

1.42 

Per cent. 

53.75 

8.01 

38.24 

Bitumen. 

Organic matter not bituminous.. 

Iuorganic matter. 

Bitumen soluble in netroleum nanbtha. . 

100.00 

100.00 

41.43 
73.60 
190° F. 
205° F. 

35.22 
65.32 
210° F. 
230° F. 

Per cent of total bitumen soluble. 

Softens at. 

Flows at..... 



The color is black with a homogeneous appearance. At a tem¬ 
perature of about 70° F. it is very brittle and breaks with a con- 
choidal fracture; it burns with a yellowish-white flame, and in 
burning emits an empyreumatic odor, and possesses little cementi¬ 
tious quality; to give it the required plasticity and tenacity it is 
mixed while liquid with from 16 to 21 pounds of residuum oil to 
100 pounds of asphaltum in the manner described in Art. 96. 

lOOo. The product resulting from the combination is called 
asphalt paving-cement; its consistency should be such that, at a 
temperature of from 70° to 80° F., it can be easily indented with 
the fingers and on slight warming be drawn out in strings or 
threads. 


























56 


HIGHWAY CONSTRUCTION. 


100p. The relative quality of Trinidad lake and land asphaltum 
for paving has been the subject of much discussion and investiga¬ 
tion, but without any positive decision being reached. 

lOOq. That there is no essential difference in the chemical 
composition will be seen by an examination of the analyses given 
in Table XV a and Art. lOOn. 

lOOr. The difference between the two varieties consists not in 
a material variation in the proportion of the constituents, but in a 
variation or change in the character of the bitumen. This change 
is due to evaporation, volatilization and oxidation of the light and 
volatile oils, thus hardening it and necessitating a larger amount 
of flux to soften the land asphaltum for use as a cement. This 
larger percentage of flux is by some authorities said to reduce the 
enduring qualities of the cement; others claim that no amount of 
flux will restore the lost qualities. Hence the object in selecting 
lake asphaltum, in which a large percentage of the natural oils 
still remains, and rejecting the land asphaltum which, has lost 
these oils in a large degree. 

100s. In Europe crude Trinidad asphaltum is used for mixing 
with the bituminous limestones in the manufacture of asphalt 
mastic; for this purpose it is refined as follows: The crude as¬ 
phaltum is melted in suitable vessels and to it is added the residue 
or by-products from the petroleum distilleries and paraffine factories 
in the proportion of about 2 parts of residue to 3 parts of asphaltum ; 
the mixture is boiled for 8 or 9 hours, during which time the earthy 
and mineral substances in the asphaltum settle to the bottom; the 
liquid asphaltum is then drawn off and is ready for use. This 
preparation is known in England as refined bitumen; in France as 
bitume rafine, bitume compose, and goudron compose; in Germany as 
goudron . 

101. Bermudez Asphalt.—This is the name given to the asphaltum 
obtained from a lake or deposit situated in the state of Bermudez, 
Venezuela. This deposit is said to have an area of over 1000 acres. 
It is situated about 60 miles from the coast up the San Juan 
River, and about 51 miles distant from it; a narrow-gauge steam 
railroad connects the deposit with the shipping point, and vessels 
drawing 18 feet of water can be loaded directly from the cars. 

The crude asphaltum is of the same variety as the Trinidad, 





MATERIALS EMPLOYED IN THE CONSTRUCTION OF PAVEMENTS. 57 


namely, bitumen mixed with sand, clay, and vegetable matter; its 
average specific gravity is 1.09, and its average composition is as 
follows: 

Per cent. 


Bitumen. 93.54 

Mineral matter. 2.1G 

Organic matter not bituminous. 1.15 

Water. . 3.15 


100.00 


Petrolene. 77.90 

Asphaltene. 21.08 

Retine. 1.02 


100.00 

The refining process is practically similar to that desbribed 
under Trinidad asphaltum, but is much more rapid, owing to the 
small amount of water and mineral matter present. In manufac¬ 
turing the cement it requires much less petroleum residuum than 
the Trinidad on account of the large amount of oil that it contains; 
it melts at a lower temperature than the Trinidad, and the follow¬ 
ing are some of its characteristics: At 60° F. compressible; at 
70° F. viscous and malleable; at 100° F. flowing, and can be 
stretched in hairlike threads; at 189°F. melts; at 400° F. gives no 
flash. (See also Art. 265a.) 

102. California Asphaltum.—Asphaltum is produced in Cali¬ 
fornia by refining the bitumen from the extensive sandstone and 
other deposits which are found in various parts of the State. The 
characteristics of both the crude and refined asphaltum from some 
of the more important deposits are shown by the following an¬ 
alysis : 

Analysis of Asphaltum from Bakersfield, Cal. 



Crude. 

Refined. 


Specific gravity. 

1.132 

1.240 


Softens at. 

4 

0 

O 

QO 

t-H 

150° F. 


Flows at... 

220° F. 

180° F. 


Inorganic matter. 

9.57 p. c. 

9.77 p. 

c. 

Bitumen soluble in CS 2 . 

85.49 p. c. 

90.16 p. 

c. 

Bitumen soluble in ether. 

69.98 p. c. 

86.45 p. 

c. 

Percentage of total bitumen soluble in 




ether. 

81.85 p. c. 

95.88 p. 

c. 






















58 


HIGHWAY CONSTRUCTION. 


Analysis of Asphaltum from Asphalto, Cal. 



Crude. 

Refined. 

Moisture. 

6.51 p. c. 

0.42 p. c. 

Bitumen soluble in chloroform. 

84.79 p. c. 

93.27 p. c. 

Organic matter (not bitumen). 

Inorganic matter consisting of infuso- 

trace 

0.54 p. c. 

rial earth with traces of iron. 

8.70 p. c. 

5.77 p. c. 

Petrolene soluble in acetone. 

67.50 p. c. 

71.27 p. c. 

Asphaltene insoluble in acetone. 

Combined sulphur (chemically held in 

32.50 p. c. 

28.73 p. c. 

the bitumen)... 

0.73 p. c. 



Analysis of Asphaltum from Santa Barbara Co., Cal. 

Crude. Refined. 

Specific gravity. . 1.250 

Organic non-bituminous matter. 1.10 p. c. 

Inorganic matter consisting of finely 
divided quartz with oxide of iron 

and alumina. 39.75 p. c. 

Bitumen soluble in CS 2 . 59.15 p. c. 

Bitumen soluble in petroleum naphtha 


(petrolene). 42.50 p. c. 

Asphaltene. 7.35 p. c. 

Analysis of Asphaltum from Kern Co., Cal. 

Bitumen soluble in CS 2 . 78.90 p. c. 

Mineral substances—sand, clay, and silica. .. 9.40 p. c. 

Coky and volatile matter. 4.53 p. c. 

Water and loss... 7.17 p. c. 

Analysis of Bituminous Sandstone from Ventura Co., Cal. 

Bitumen. 24.00 p. c. 

Silica. 64.00 p. c. 

Oxide of iron i 

Calcium carbonate \ . 12.00 p. c. 


Cements for paving and other purposes are manufactured from 
the refined asphaltum described above by the admixture of maltha; 
the two substances are combined at a very low temperature, the 
heat being applied indirectly, and the mixing is performed mechan¬ 
ically; the degree of softness can be made to suit any requirement. 

103. Asphalt Mastic. — In Europe mastic is made from a 
mixture of bituminous limestone and refined asphaltum (usually 
Trinidad). The bituminous limestone is reduced to powder and 
mixed with about 8 per cent of refined asphaltum, then 























t 


MATERIALS EMPLOYED IN THE CONSTRUCTION OF PAVEMENTS. 59 


melted and thoroughly mixed. The hot composition is run into 
moulds of various shapes, usually round or hexagonal, and of such 
dimensions as will give a cake or block weighing about 56 pounds; 
these blocks usually have the name of the source or factory moulded 
on them. 

The mastic is prepared for use by breaking the cakes into small 
pieces, and heating it with the addition of about 5 per cent of re¬ 
fined asphaltum. The mass is constantly stirred and when soft, 
sand and fine gravel are added and thoroughly incorporated by 
stirring for about two hours at a temperature of about 300° F., when 
it is ready for use. 

Asphalt mastic is also prepared from bituminous sandstones 
and maltha or refined asphaltum, and from asphalt paving-cement. 
The principal use of mastic is for sidewalks and floors. In Europe 
it is called AsqAialie conlZ in distinction from the compressed 
bituminous limestone, which is called Asplialte comprime. (See 
also Art. 266, et seq., and Art. 778, et seq .) 

103a. Analysis and Tests of Asphaltum.—The tests employed 
to determine the relative merits of asphaltum and asphaltic cements 
comprise both chemical and physical investigations. 

The chemical examination of the crude material involves the 
following determinations: 

Specific gravity. 

Percentage of moisture. 

“ “ matter soluble in turpentine. 

“ “ “ “ “ carbon bisulphide. 

“ “ “ “ “ alcohol. 

(f a <( u « ether. 

“ “ “ volatile in 10 hours at 400° F. 

•< “ sulphuretted hydrogen evolved at 400° F. 

“ “ non-bituminous organic matter. 

“ “ mineral constituents. 

Softening point. 

Flowing point. 

The examination of the physical properties (mechanical tests) 
involve the following determinations: 

(1) The refining of the crude material and making of an 

asphaltic cement. 



GO 


HIGHWAY CONSTRUCTION. 


(2) Determining the penetrability of the cement. 

(3) Making a paving mixture and testing it for tensile and 
crushing strength. 

The penetration tests are usually conducted in a machine in¬ 
vented by Prof. Bowen. This machine consists of a lever about 17 
inches long, having the fulcrum at one end and a cambric needle in¬ 
serted in the other end, above which is placed a weight of 100 grams. 
The end near the needle is connected by a steel rod and waxed cord 
with a spindle having a long hand which moves about a dial divided 
into 3G0 degrees. Another cord and weight upon an enlarged part of 
the spindle keeps the first-mentioned cord taut. By a suitably con¬ 
trived spring clip the steel rod can be released for any length of 
time, and the needle, which has first been brought to coincide with 
the surface of the asphalt cement placed under it in a tin box, 
allowed to penetrate under the action of the weight into the cement. 
The number of degrees through which the hand moves on the dial 
record the penetration of the cement; the length of time for which 
the needle is released is one second. Originally Prof. Bowen 
selected 77° F. as the proper temperature at which the test should 
be made, and brought the cement and machine to this degree by 
keeping them in a room warmed to this point. But as it is some¬ 
times inconvenient or impossible to have a room temperature of 
77°, other temperatures may be made available by placing the tin 
sample-box of asphalt cement in water at 77° and allowing it to 
acquire that temperature, when the test can be made as before, cer¬ 
tain allowance being made to reduce the result to the normal 
temperature of 77° F. 

The physical tests are performed in the usual machines em¬ 
ployed for testing other cements. 

As asphalt cement possesses the same qualities and can be 
used for the same purposes as hydraulic and other cements; its 
physical qualities can be tested in a similar manner; but the tests 
which have been made and published have been conducted without 
any regard to uniformity and under widely different conditions; 
therefore they are of little or no value in determining the relative 
merits of the cements. 

Uniformity in making the tests would accumulate much valuable 
data which could be compared, and much definite information 



MATERIALS EMPLOYED IN THE CONSTRUCTION OF PAVEMENTS. 61 


would thus he gradually collected from which definite conclusions 
could be ultimately drawn. 

A regular system of analysis and examination of both the crude 
and refined asphaltum, the oils or other agent used for fluxing, 
the method of refining the asphaltum, the method of manufactur¬ 
ing the asphaltic cement, the sand, stone-dust, etc., should be main¬ 
tained in all cities using asphalt pavements. The experience thus 
gained of the success or failure of pavements made of different 
asphalts will serve as a guide for similar work in the future. This 
experience, however, will not serve as a criterion for all cities, be¬ 
cause, owing to different climatic and local conditions, the propor¬ 
tions of the ingredients in the cement and paving mixture must be 
varied to suit the conditions of the place where used; therefore the 
mixtures which are successful in one locality may become failures in 
another. 

In comparing the relative qualities of asphaltums for paving 
purposes much stress is frequently laid upon the amount of bitumen 
they contain. As the amount of bitumen entering into the paving 
mixture is less than 20 per cent of the whole, the amount of bitumen 
contained in a crude asphaltum can in no way affect the quality of 
the pavement; but its quantity does affect the commercial value or 
price of the crude material in regard to the amount of refined 
asphaltum that it will yield. As far as the qualities of the paving 
mixture are concerned, it is the character and condition of the 
bitumen, and not its quantity, that affect the results. 

104. Prices, Production, and Imports of Asphaltum.—The fol¬ 
lowing tables show the comparative prices of different varieties of 
asphaltum, the amount of the domestic production, and the im¬ 
ports to the United States during the year 1893: 

TABLE XVII. 

Prices of Asphaltum in 1893. 

Trinidad crude, at New York. $13.00 per ton 

“ refined, at New York.$30.00 to $40.00 

Hard Cuban, at New York. 28.00 

Gilsouite. at the mines. 60.00 

Bituminous rock : 

California, at the mines... 2.50 to 12.00 

Kentucky, at the mines . 2.40 

California refined (hard), at the works. 17.50 to 19.50 

at New York.... 26.50 to 82.00 









HIGHWAY CONSTRUCTION* 


62 


California refined (maltha), at the works... 20.00 to 22.00 per ton 

at New York.. 29.00 to 34.50 
Wasatch bituminous limestone, at the works 18.00 


TABLE XVIII. 

Production of Asphaltum and Bituminous Rock in the 

United States in 1893. 


Varieties. 

Short Tons. 

Value. 

Asphaltum. ... 

11,350 

1,500 

34,929 

$248,250 

15,000 

108,982 

Bituminous limestone... 

Bituminous sandstone. 

Total. . 

47,779 

$372,232 



Divided by States, the product was as follows: 


States. 

Short Tons. 

Value. 

California... 

42,650 

3,200 

1,929 

$275,662 

90,000 

6,570 

Utah.'. 

Kentucky. 

Total. 

47,779 

$3?2,232 



In 1892 California produced 87,680 tons of bituminous rock, 
which is the largest on record. 

TABLE XIX. 

Imports of Asphaltum, etc., to the United States in 1893. 

Tons. Value. 

Trinidad....... . l $196,314 

Europe and other countries. 9,354 ) 

In 1892 there was imported 120,225 short tons, valued at 
$336,868, and in addition to this there was imported an amount 
the weight of which is not stated, valued at $74,042. 

105. Uses of Asphaltum.— Refined asphaltum and asphaltic 
cement are extensively used in all branches of engineering. The 
paving industry absorbs about 60 per cent of the domestic produc¬ 
tion and about 80 per cent of the imported. Of the imports from 
Trinidad about 90 per cent is employed for street-paving. 

106. Paving-pitch.—This is the name given to the tar pro¬ 
duced in the manufacture of gas. It is also known as gas-tar, coal- 
tar, etc. When the tar is redistilled, the product is called coal-tar 































MATERIALS EMPLOYED IN' THE CONSTRUCTION OF PAVEMENTS. 63 


distillate , and is numbered Distillate No. 1, 2, 3, 4, etc., according 
to the density or specific gravity. The character of the tar 
varies with the system of carbonization and temperature employed. 
There are several tars on the market which show to the analyst no 
material difference, although the grouping and character of the 
constituents are different. Some, when used for paving purposes, 
will become hard and brittle in a few months, and others will not 
harden or set. 

The principal use of paving-pitch is for filling the joints in 
stone-block and brick pavements. As a cementing medium for 
carriageway pavements its use has been practically abandoned, but 
it is still extensively employed in country towns in England for 
footpaths, floors, etc. 

Many persons consider that the enduring quality of the tar is 
increased by the addition of refined asphaltum, and specifications 
frequently call for the addition of from 10 to 20 per cent of as¬ 
phaltum; but this clause is rarely complied with, and it is doubt¬ 
ful if the mixture would prove beneficial, because the materials, 
although very similar in appearance and in some of their charac¬ 
teristics, are entirely different in composition. 

(See also Art. 160.) 

107. Brick—Clay .—Pure clay consists of a hydrated silicate of 
alumina in combination more or less with other substances derived 
from the felspathic rocks, which by their disintegration and 
decomposition have formed the clay. The chemical formula of the 
most prominent varieties of clay according to Brogniart and others 
may be expressed by 2Al 2 0 3 3Si0 2 4H0. 

108. Pure clav is soft, more or less unctuous to the touch, 
white and opaque, and when breathed upon emits a characteristic 
odor. It is infusible, and insoluble either by water, nitric or 
hydrochloric acids. It may be converted by water into a doughy, 
tenacious, plastic paste. It absorbs water with avidity, but when 
burned at a sufficiently high temperature it becomes hard and 
gritty and loses almost wholly or altogether this property of 
combining with water. When slowly dried and exposed to red 
heat, the particles of clay are augmented in volume and possess less 
density. At the same time, however, the interstitial spaces are 
diminished and they approach more closely together, giving an 
increase of density to the whole mass of burnt clay, which is prac¬ 
tically observed by a diminution of surface and technically called 






64 


HIGHWAY CONSTRUCTION. 


the shrinking of the clay. This shrinkage is very materially modi¬ 
fied and affected by the admixture and proportion of foreign 
matters possessing other properties, 

109. In nature the greater number of clays is found inter¬ 
mingled with other substances foreign to them in their original 
localities. The usual constituents of clay are alumina, silica, iron, 
lime, magnesia, and alkalies, all of which modify the character of 
the clay and its applications, according as one or other of these in¬ 
gredients predominates. 

110. The ingredients which most affect the character of the 
clay are the silica, iron, and lime, and its plasticity diminishes in 
proportion to the amount of any one of these substances which it 
contains, as they are not plastic. Sand exercises the most marked 
effect; it possesses no binding properties, and alone it is infusible 
except at the highest temperatures of the oxyhydrogen blowpipe- 
Bricks made of clay containing an excess of sand are rough and 
weak. Iron renders clay fusible, and its presence is objectionable in 
brick intended for furnace-lining; but in paving-brick it is advan¬ 
tageous, making the brick more homogeneous. Lime, although 
infusible, is at high temperatures changed into caustic lime, ren¬ 
ders the clay fusible, and when exposed to the action of the 
weather absorbs moisture and causes disintegration. Its presence 
is to be avoided in clay used for the manufacture of paving-brick. 
Magnesia exerts but little influence on the character of the clay; in 
small quantities it renders the clay fusible; at 60 degrees Fahr. its 
crystals lose their water of crystallization and cold water decom¬ 
poses them, forming an insoluble hydrate in the form of a white 
powder. In air-dried brick this action causes them to crack. The 
alkalies are found in small quantities in the best of clays; from 
1 to 3 per cent renders the clay fusible. The greater the amount 
of quartz and silica that enters into the composition of the clay, the 
more difficult it will be of fusion. 

111. Clay, to make a good paving-brick, must be rich in silica, 
free from lime, and able to withstand without fusing a red heat 
for a sufficient length of time to render the bricks hard, homoge¬ 
neous, and impervious to water. 

112. Common hard-burned brick is not suitable for paving pur¬ 
poses, although such brick makes a smooth pavement under light' 
traffic and lasts for a number of years; still, under the influence of 



MATERIALS EMPLOYED IN' THE CONSTRUCTION OF PAVEMENTS. 65 


moisture and frost, disintegration is inevitable in the end. Nor 
will such brick sustain constant heavy traffic, aside from climatic 
influences. Brick made of suitable clay, however, will stand the 
severest frosts, and crushing tests show it to be equal to many 
granites. 

113 . The color of clay is of no practical importance; it is due 
to the presence of metallic oxides and organic substances. Clay 
containing iron produces bricks which are either red, yellow, or 
blue, according to the quantity of the oxide present and the de¬ 
gree of heat to which they have been subjected; some organic sub¬ 
stances produce a blue, bluish-gray, or black color. 

114 . The manufacture of paving-brick may be classified under 
six heads: 

(1) Excavation of the clay, either by hand or steam-power. 

(2) Preparation of the clay consists in (a) removing gravel, 
stones, or other mechanical impurities; (b) grinding the clay. This 
is performed in either dry or wet pans, and is important: the finer 
the clay is ground the more homogeneous the brick. 

(3) Tempering. This is performed in a variety of ways, either 
with or without the aid of machinery; where the amount of clay to 
be handled is large, “ pug-mills ” driven by steam-power are em¬ 
ployed. 

(4) Moulding. The clay is moulded either by hand or machines; 
hand-moulded brick are generally pressed, but machine-moulded 
ones do not require it. In moulding paving-brick the utmost 
amount of clay should be compressed into the mould. 

(5) Drying. The moulded bricks are slowly dried either in cov¬ 
ered sheds open to the air, or in chambers heated for the purpose. 

(6) Burning. After being sufficiently dried the bricks are piled 
in kilns, and the firing is conducted with the utmost care, as upon 
it the perfection of the brick largely depends. The time required 
for burning is six or more days. The kilns used are of various 
kinds, some makers preferring up-draft and some down-draft; the 
size depends upon the extent of the business carried on. 

115 . A variety of methods is practised in the execution of the 
above-described operations, and a description of them would be 
confusing. From the variety and differences of clay, the experience 
gained in one locality is often of little use in another. 








GG 


HIGHWAY CONSTRUCTION. 


116. Analyses of Clay.—Table XX shows the conrposition of 
some of the clays used in the manufacture of paving-brick. 


TABLE XX. 
Analyses of Clays. 


Locality. 

Silica. 

Aiumina. 

Iron. 

Lime. 

Magnesia. 

1 

Potash. 

Soda. 

Sulphur. 

Chlorides. 

Water com¬ 

bined. 

Water Hygro- 

metric. 

Titanic Acid. 

Phosphoric 

Acid. 

Silica (quartz, j 

Woodbridge, N. J. 

42.23 

39 53 

0.5 

0.1 


0.41 

0.08 



13.59 

1.21 

4 .40 


0.50 


42.05 

35.83 

0.77 


0.11 

0.44 




12.20 

1.50 

1.10 


5.70 

Phillipsburg, “ 

56.78 

17.38 

6.50 

4.14 

3.15 

3 

.42 

0.89 


7 

.60 


0.13 


Winchester, Ill.... 


17.08 

3.47 


0.28 

1 10 




6.30 

1.20 

0 90 


46.70 

Bloomington, Ill 

67.80 

11.55 

4.31 

8 90 

5.32 

2 

.42 


trace 

0 

.20 

trace 



Cheltenham, Mo.. 

61.22 

25.64 

1.70 



1 

.31 

0.4 

9.68 





4 • tfc 

38.10 

31.53 

2.32 


tr. 

0.40 




11.30 

2.50 

1.50 


12.70 

Montgomery, Mo.. 

43.93 

40.09 

0.88 

• • • 

. . 

0.20 

• • • . 

* • • 


13.80 

0.80 

tr.* 


0.60 

Woodlawn, Penn.. 

42.15 

31.43 

1.57 


0.32 

2 01 




9.40 

1.20 

1.00 


10.25 

Mt. Savage, Md... 

39.90 

30.08 

1.67 



2.30 




7.00 

6.90 

1.15 


16.90 

Carter Co., Ky — 

46.75 

38.17 

0.29 

0.57 

0.12 

0 

.07 



14 

.03 




Marion Co., W. Va. 

59.25 

32.26 


7.16 






1 

.33 




San Fran., Cal _ 

56.51 

21.33 

12 31 

3.53 

tr. 





6.30 





Haydensville, O.. . 

72.24 

16.87 

0.16 

0.50 

tr. 

1 

.09 



5.14 





Burlington, la ... 

77.40 

11.74 

3.29 

1.60 

1.91 

3 76 

0.47 








Clinton, “_ 

73.82 

15.88 

2.92 

tr. 

tr. 

4.5 




3.0 





Morrison, Colo_ 

71.8 

15.0 

tr. 

3.8 





8.3 





Golden. “ — 

52.41 

32.21 

0.66 

0.20 

0.61 

0 61 




14.05 





Stourbridge, Eng. 

67.34 

23.03 

2.03 



1 

.38 



8.24 




. 

it ti 

64.05 

23.15 

1.85 


.... 

o 

.10 



10.00 






* With A1 2 0 3 . 


117. The Characteristics of Brick suitable for Paving are: 

(1) Xot to be acted upon by acids. 

(2) Xot to absorb more than -g-i- 7 of its weight of water in 48 
hours. 

(3) Xot susceptible to polish. 

(4) Rough to the touch, resembling fine sandpaper. 

(5) To give a clear ringing sound when struck together. 

(6) When broken to show a compact, uniform, close-grained 
structure, free from air-holes and pebbles. 

(7) Xot to scale, spall, or chip when quickly struck on the 
edges. 

(8) Hard but not brittle. 

118. Tests of Brick.—The following is the schedule of tests to 
which the paving-brick used in Washington, D.C., are subjected. 
(G. J. Fiebeger, Capt. of Engineers, U. S. A.) 

(1) Carefully measure. 







































































MATERIALS EMPLOYED IN' THE CONSTRUCTION’ OP PAVEMENTS. 67 


(2) Dry for 48 hours. 

(3) Weigh. 

(4) Immerse in water for 48 hours (break some of the samples 
before immersing). 

(5) Weigh for percentage of absorption. 

(6) Dry. 

(7) Grind two bricks of each class for eight hours (this was 
done on a horizontal stone 14 feet in diameter, making 28 revolu¬ 
tions a minute; the bricks were put in a cradle and carefully 
watched so that each should be subjected to the same test). 

(8) Dry. 

(9) Weigh to determine percentage of loss. 

(10) Two bricks of each class put in a rambler for half an 
hour, this rambler making 28 revolutions per minute. 

(11) Weigh to determine percentage of loss. 

(12) Relative general appearance, determined by considering 
character and appearance as a paver. Study of fracture and struct¬ 
ure of sample. 

(13) Determine weight per cubic inch. 

Add together the numbers indicating order in each test. The 
sample having the lowest total will be considered as having passed 
the test most satisfactorily, unless fatally defective in any one test. 
After determining the relative quality, the size and price of the 
best specimens will be considered. Table XXI shows the results 
of tests carried out in the above manner on several varieties of 
brick. 

119. Specific Gravity, Weight, Resistance to Crushing, and Ab¬ 
sorptive Power of Paving-brick. In regard to these qualities the 
paving-bricks made by different manufacturers and bv the same 
manufacturer vary considerably, as will be seen from Table XXI. 
In weight they vary from 5 to 7\ pounds; in specific gravity, from 
1.91 to 2.70; in resistance to crushing, from 7000 to 18,000 pounds 
per square inch; in absorption, from 0.15 to 0.60 per cent. 

Tests of Ohio Paving-brick.—Table XXL? contains the re¬ 
sults of a series of tests conducted by Prof. Edward Orton, Jr., at 
the solicitation of the Geological Survey of the State of Ohio. The 
tests were performed with the greatest care and absolutely without 
interest or bias of any kind, and the results are solely on the 






68 


HIGHWAY CONSTRUCTION. 


TABLE XXI. 

Tests of Paying-bricks at Washington, D. C. 
(By G. J. Fiebeger, Captain of Engineers, U. S. A.) 


Number of 
Proposal. 

Av. Weight. 
Lbs., oz. 

Absorption. 

Per Cent. 

Tumbling I Hr. 
Per Cent Loss. 

Grinding 8 Hrs. 

Per Cent Loss. 

Density. 

Wt. Cu. In. Oz. 

Uniformity of 

Structure. 

Order of Merit. 

Price per M. 

Grade. 

1 

6.15 A 

.029 

.040 

.131 

1.286 

5 

$18 50 

Ordinary 

2 

6.14 A 

.015 

.075 

.102 

1.307 

8 

21.00 

Re-pressed 

3 

5.11 A 

.043 

.084 

.227 

1.215 

9 

21.00 

Re-pressed 

4 

6.13 

.025 

.065 

.167 

1.201 

4 

19.00 

Ordinary 

5 

6 .8ft 

.060 

.090 

.364 

1.198 

12 

17.93 

Re-pressed 

6 

6 .2ff 

.047 

.036 

.231 

1.141 

11 

18.50 

Ordinary 

7 

6 .10A 

.042 

.060 

.194 

1.154 

6 

17.72 

Ordinary 

8 

5.14 A 

.052 

.050 

.170 

1.196 

10 

18.38 

Ordinary 

9 

6 .9 A 

.036 

.023 

.132 

1.206 

2 

18.00 

Ordinary 

10 

6.12 A 

.033 

.018 

.112 

1.274 

1 

19.00 

Re-pressed* 

11 

6 .8ft 

.018 

.070 

.159 

1.197 

3 

19.75 

Ordinary 

12 

7.3* 

.019 

.123 

.138 

1.178 

7 

19.75 

Ordinary 


* Contract awarded. 

In size the bricks varied from 8|| to 8|f inches in length, from 8f| to 4ff 
inches in width, and from 2ff to 2f§ inches in thickness. 


merits of the samples furnished. The tests are interesting and 
valuable in several ways. It is the first work of the kind under¬ 
taken by the State, and it is also probably the first large and gen¬ 
eral test in which the results could not be attacked as being ex 
parte. It is of great interest to those who compete for standing, 
of course, and it should be equally interesting to all clay-workers 
to see so large a list of factories, representing an annual capacity of 
three hundred millions of brick, showing so high an average 
quality of material. The samples were selected by the manufac¬ 
turers themselves, and therefore represent their best. It was the 
intention to make this so; the public does not desire to know how 
poorly the brick-makers can do, but how well, and, having shown 
their ability to produce goods of this quality, it should be their 
constant endeavor to hold their average output up to the same 
high grade. 

120. Wood.—Both the hard and soft varieties of wood have 
been employed for paving. In the United States, cedar and cypress, 
on account of their abundance and cheapness, are more generally 
used. Recently mesquite, which grows in abundance in both Texas 
and Mexico, has been used. In Europe nearly all varieties of the 


























MATERIALS EMPLOYED IN' THE CONSTRUCTION OF PAVEMENTS. 69 


W 

o 

w 

ft 

PQ 

. o 

< ft 

■t-H M 

X t 

x id 


w 

Eh 


W 

o 

ft 

o 

CD 

H 

CD 

H 


•qoni -no 
‘mSueaig 
SaiqsnjQ 

1,315 

00 

CO 

T —1 

1,342 

00 

GO 

GO 

T— < 

1,277 

1,694 

1,249 

1,131 

0? 

0 

T-H 

1,160 

1,491 

shing 

made. 

•qoni -bs 
‘q^Saaa^g 
Saiqsn .10 

5,260 

4,465 

5,462 

7,499 

5,208 

6,632 

1 

4,836 

4,628 

5,286 

4,592 

6,125 

No cru 

tests 




GO 

Of 

O 

i.- 

O 

GO 

T-H 

Ci 


C 5 


a 

L- 

CO 

T-H 

00 

Ol 

CO 

CO 

in 

CO 

05 


‘SaiiD'BH 

GO 


d 


ci 

d 

T-H 

T-H 

in 

Tt* 

d 


^U 80 J 9 (I 


CO 

rft 



0* 

©» 

c\* 

*"• 

t-H 

Cl 

T-H 

•ni^o 

0 

GO 

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t- 

Tj« 

00 

CO 

rt< 

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70 


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TABLE XXIa— Continued. 


MATERIALS EMPLOYED IN THE CONSTRUCTION OF PAVEMENTS. 71 


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TABLE XXIa— Continued. 


72 


HIGHWAY CONSTRUCTION". 


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MATERIALS EMPLOYED IN THE CONSTRUCTION OF PAVEMENTS. 73 


TABLE XXII. 

Specific Gravity, Weight, and Resistance to Crushing of Various 

Woods. 


Acacia. 

Ash, American white, dry. 

Beech. . 

Cedar, American white. 

Chestnut, “ ... . 

Chestnut. 

Cypress, American. 

Deal, Christiania. 

Ebony . 

Elm. 

Fir, American (Pacific region).. 

Fir, European. 

Hemlock, Am. (Atlantic region) 

Hickory. 

Lignum vitae. 

Mahogany, Spanish. 

“ Honduras. 

Maple. 

Mesquite, American (Texas).... 
Oak e * white (Atlantic) 

“ “ chestnut “ 

“ “ red “ 

“ “ black “ 

English. 


Pine, American white. 

“ “ red. 

“ “ yellow (Pacific) 

“ “ pitch (Atlantic) 

“ Dautzic. 

Redwood, American (California) 
Spruce, “ (Atlantic).. 


Specific 

Gravity. 

Average Weight, 
pounds per 
cubic foot. 

Resistance to 
Crushing, pounds 
per square inch. 

.71 to .79 

44 

16,000 

.61 

38 

8,900 

.69 

43 

7,700 

.36 

22.45 

4,400 

.46 

22.80 

5,300 

.60 

38 


.408 

24.4 

6,000 

.689 

43 

5,850 

1.187 

74 

19,000 

.56 

35 


.405 

25.28 


.512 

32 

6,500 

.409 

25.5 

5,300 

.85 

53 


1.33 

83 

10,000 

.85 

53 

8.200 

.56 

35 

8,000 

.79 

49 


.756 

47 

10,450 

.763 

46.5 

7,000 

.711 

44 

7,500 

.751 

46.7 

7,000 

.687 

43.8 

7,000 

.777 

48 

6,400 

.934 

58 

10,000 

.35 to .45 

21 to 25 

5,400 

.485 

30 

6,300 

.530 

33 

12,000 

.632 

39 

5,000 

.649 

40 

5,400 

.473 

29.5 

9,500 

.408 

i 

25.4 

5,700 


pine species have been tried, as well as oak, ash, and elm, but Memel 
and Dantzic fir appears to be the favorite. 

Recently jarrali from Australia and pyingado (xylia dolabri- 
formis) from India have been introduced in London; the results 
are still indefinite. 

121. Whichever kind is used, it should be sound, close-grained, 
uniform in quality, free from knots and sap and from the blue 
tinge which is a sign of incipient decay. All sappy wood should 
be rejected. 










































74 


HIGHWAY CONSTRUCTION. 


TABLE XXIII. 
Absorptive Power of Wood. 


(E. R. Andrews in “Engineering News.”) 



Percentage of Water absorbed. 

Dry Wood. 

Creosoted. 

Black gum.... 

1.0000 

.7140 

.2000 

.1754 to .3333 

.1600 

.4300 

.4722 

.1250 
.3470 
. 0625 

.0236 to .0306 

.0000 

.1240 

.0000 

Cottonwood. 

Oak . 

Spruce... 

“ (Burnettized .2500). 

Hard pine. 

White birch. 

Sesquoia gigantea (tree of California).... 


122. The use of creosote or other preserving processes makes it 
difficult to discover defects in the wood, and on this account is 
objectionable. It is doubtful if creosoting, etc., adds to the life of 
wood employed for paving. 

123. Sand.—Sand is an aggregation of loose incoherent grains 
crystalline in structure and angular in shape, of silicious, argilla¬ 
ceous, calcareous, or other material, derived from the disintegration 
of rocks or other mineral matter, and unmixed with earth or 
organic matter. For road purposes the grains should not exceed 
one eighth of an inch in size. 

124. The principal use of sand is as a foundation for broken 
stone, a cushion and bed for stone paving-blocks, and as a joint fill¬ 
ing. For these purposes it is eminently suitable, because when 
confined so that it cannot escape or spread it possesses the valuable 
properties of incompressibility, and mobility or the quality of as- 
sumirg a new position when any portion of it is disturbed. 

As a base or cushion for blocks it quickly adjusts itself to every 
irregularity of their inferior surfaces, and when the blocks finally 
settle in place it furnishes a solid incompressible medium to trans¬ 
fer the pressure to the foundation below. For this purpose it should 
be fine and dry; if coarse and damp, the blocks will adjust them¬ 
selves with difficulty and the fewer will be the points of support 
between them and the foundation, and the greater will be the 
pressure of contact and liability to unequal settlement. 





















MATERIALS EMPLOYED IN THE CONSTRUCTION OF PAVEMENTS. 75 


125. Sharp sand, i.e., sand with angular grains, is much better 
than that with rounded grains, although it is often difficult to 
obtain. The sharpness of sand can he determined approximately 
by rubbing a few grains in the hand or by crushing it near the ear 
and noting if a grating sound is produced. 

126. The sand for bedding blocks and jointing should be clean, 
i.e., free from loam or clay. The cleanness may be tested by rub¬ 
bing a little of the dry sand in the palm of the hand and, after 
throwing it out, noticing the amount of dust left on the hand. The 
cleanness of sand may also be judged by pressing it together be¬ 
tween the fingers while it is damp; if the sand is clean, it will not 
stick together, but immediately fall apart when the pressure is 
removed. 

127. For concrete used for foundation it is not necessary that 
the sand should be free from clay; indeed a small amount of clay 
may be beneficial. Clay when dissolved or finely pulverized con¬ 
sists of an almost impalpable powder, and when mixed with sand 
its particles occupy the interstices between the particles of cement 
and sand, and are also completely enveloped by the cementing paste. 
Clay, dissolved or finely pulverized, mixed with cement up to the 
proportion of 1 to 1, appears to affect the strength essentially the 
same as an equal quantity of sand, and the mortar is much more 
dense, plastic, and water-tight. Such mortar is not affected by the 
presence of water. 

The voids of ordinary sand average from 0.3 to 0.5 of the 
volume; the more uneven the sizes the smaller the voids. 

128. The quantity of sand required for bedding paving-blocks 
is about one cubic yard to six square yards of paving. 

129. The price of sand varies from 40 cents to $1.60 per yard, 
according to locality. 

130. Sand is sometimes sold by the ton. It weighs when dry 
from 80 to 115 pounds per cubic foot, or about 1 to 1| tons per 
cubic yard. 

131. Gravel is an accumulation of small stones which vary 
in size from a small pea to a walnut or something larger. It is 
often intermixed with other substances, such as sand, clay, loam, 
etc., from each of which it derives a distinctive name. In select- 






76 


HIGHWAY CONSTRUCTION - . 


ing gravel for road purposes the chief quality to be sought for is 
the property of binding (see Art. 421). 

“ The so-called Tomkins Cove gravel, which is much used about 
New York, is a broken limestone, apparently of the cement series. 
It is usually spread over the road, and compacted by the traffic. 
The darker-colored stone is very pleasant to the eye, and it readily 
makes a smooth wheel way singularly free from either mud or dust 
even when subjected to rather heavy traffic, though it is too friable 
for economical use in such situations. Its performance is so differ¬ 
ent from that of the ordinary limestones that an analysis is ap¬ 
pended : 


Lime.. 

Alumina. 

Silica . 

Magnesia. 

Carbonic acid 
Water. 


60.20 per cent 
11.22 
6.13 
10.45 
8.00 
4.00 


100.00 per cent 


132. Shingle is the gravel or accumulation of small stones 
found on the shores of rivers or the sea. 


132a. Chert is a silicious material approaching the character 
of flint; it is composed of lime, silica, iron and alumina, its ap¬ 
pearance varies from that of limestone to sand-stone; in color it 
ranges from pure white to milky blue, in texture from porous to 
flinty. The name chert is also frequently applied to the slag 
derived from blast furnaces. 











MATERIALS EMPLOYED IN THE CONSTRUCTION OF PAVEMENTS 


i i 


TABLE XXIV. 

Specific Gravity, Weight, and Resistance to Crushing of Various 

Substances. 


Substance. 


Specific 

Gravity. 


Weight, 
pounds per 
cubic foot. 


Resistance 
to Crushing, 
lbs. persq. in. 


Asphaltum.905 to 1.65 

Basalt (greenstone)... 

1.277 

2.9 

2.95 

.848 

2.25 

2.4 

1.6 to 2 

1.4 

2.2 

“ Scotch. 

Bitumen, liquid. 

Bituminous limestones. 

Brick, best pressed. ... 

“ common hard. 

“ soft inferior . 

“ Stourbridge fire. 

44 pa.ving. . 

“ work in cement-mortar masonry. 

Chalk . 

1.8 

1.8 to 2.1 

Clay . 

44 drv. in lmrms loose . 

44 with gravel .. 

2.48 

GAmpnt Vivdrfl.nlir* Amp,rina.n R.osftndalfi.. 

“ English Portland . 

1.6 to 1.76 

44 Erenph “ . 

“ Roman . 

1.6 

1.9 

2.2 

1.28 to 2 

flnnerete. ordina.rv . 

“ pement (Portland! . 

Earth, common loam, dry, loose. 

“ common loam perfectly dry, shaken. 

Earth, common loam, perfectly dry, moderately 

r a m m pd . . 

Earth, common loam, slightly moist, loose. 

44 44 44 m nr a moist loose . 


44 44 “ “ “ shaken. 

44 44 4 4 “ “ mod. packed... 

4 4 44 “ as a soft flowing mud.. 

Earth, common loam as a soft flowing mud well 



2.6 

2.5 to 2.8 
2.5 to 3.45 
2.69 






2.8 



.900 

1.000 

7.21 

7.69 

.917 to .922 
11.30 toll.47 
1.5 

** Ql'ifl.k’pn . 





Lime, quick, of ordinary limestones . 







Masonry or gictuiio oi iiiiicolvjiic . . 

44 of rubble, $ of the mass being mortar.... 




U1 ScUlUSbUllU U i coocu ..... • • • •.. 


OI D11CKWUIK, ClUot? juiu i/o • . 


it tt tt c/vff. hriVlrs . 



2.75 to 3.1 
1.38 to 1.9 


44 wet, moderately pressed . 

1.63 


.848 


80 to 87.3 
181 
184 
53 
156 
150 
125 
100 
137 


112.5 
156 
119 
63 
155 
56.60 
81 to 102 
76 to 88 


100 

119 

137 


72 to 80 

82 

tt 

92 

90 

tt 

100 

70 

tt 

76 

66 

tt 

68 

75 

tt 

90 

90 

tt 

100 

104 

tt 

112 

110 

tt 

120 


126 

166 

186 

168 

96 

175 

100 

56.25 

62.5 

450 

485 

57.4 

709.6 

95 

53 

64 

75 

165 

154 

138 

144 

140 

125 

100 

183 

106 

80 to 110 
110 “ 130 
104 “ 120 
52.9 


17,200 

8,300 


14.973 

12,000 

600 to 3,000 
1 717 

9,000 to 15,000 


501 


27,000-30,000 


110,000 

45,000 


6,944-7,730 





































































































































78 


HIGHWAY CONSTRUCTION. 


TABLE XXI V.—Continued. 

Specific Gravity, Weight, and Resistance to Crushing of Various 

Substances. 


Substance. 

Specific 

Gravity. 

Weight, 
pounds per 
cubic foot, 

Resistance 
to Crushing, 
lbs. per sq. in 

Petroleum. 

.878 

54.8 

20 to 30 

69 

170 

165 

90 

105 

112 

94 

90 to 106 
118 “ 129 
117 

100 

95 

102 

162 

162 

92 

88 

175 

170 

490 

5 to 12 

15 “ 20 

62.417 

62.355 

59.7 

64.08 


Peat, dry, unpressed. 


Pitch. . . 

1.15 

2.66 to 2.8 
2.65 


Porphyry. 


Quartz, pure.. 


“ finely pulverized, loose. 


“ “ “ shaken.-. 



“ “ packed. 



“ quarried, loose. 



Sand of pure quartz, dry and loose. 

“ “ “ “ perfectly wet. 

2.75 


“ river...'. 

1.88 

1.61 

1.52 

1.64 

2.5 to 2.6 
2.6 

.. • • • 

“ pit. coarse. 

“ “ fine. . 


“ (Thames) England. 


Serpentines. . 


Shales, red or black . 


“ quarried in piles. 


Shingle.. 

1.42 

2.7 to 2.9 
1.73 

7.85 


Slate. 

10,000-21,000 

Soapstone or steatite. 

Steel. 

336,000 

Snow, freshly fallen. 

“ compacted. 



Water, pure rain, or distilled at 32° Fah., barom. 
30 inches. 



Water, pure rain, or distilled at 62° Fah., barom. 
30 inches. . 

1.00 


Water, pure rain, or distilled at 2i2° Fah., barom. 
30 inches . 


Water, sea.1.026 to 1.030 

1.028 







































































CHAPTER III. 


STONE PAVEMENTS. 

133. Stone Pavements.—Stone in a variety of forms has been 
employed as a paving material for more than 2500 years. The 
Romans used it in the form of large, irregularly-shaped blocks laid 
on a massive foundation of concrete. In this form it is unsurpassed 
in regard to solidity and durability, but it is objectionable for 
modern traffic. The surface of the large blocks wears smooth, and 
hence affords but an uncertain foothold for horses. These large 
blocks were superseded by round pebbles or cobblestones, obtained 
from the beach and gravel-pits. This class of pavement has been 
used extensively in the United States. It is recorded that Boston, 
Mass., in 1663 had many streets paved with pebbles. In 1718 
cobblestone pavements were introduced into Philadelphia, and this 
city is the only one to retain them on a large scale at the present 
day. 

134. Cobblestone Pavement.—Cobblestones bedded in sand 
possess the merit of cheapness and afford an excellent foothold 
for horses, but the roughness of such pavements requires the 
expenditure of a large amount of tractive energy to move a load 
over them. Aside from this, cobblestones are entirely wanting in 
the essential requisites of a good pavement. The stones being of 
irregular size, it is almost impossible to form a bond or hold them 
in place. Under the action of the traffic and frost the roadway 
soon becomes a mass of loose stones. Moreover, cobblestone pave¬ 
ments are difficult to keep clean, and very unpleasant to travel 
over. 

135. Specifications for Cobblestone Pavement.—The following is 
the common form of specification for this class of pavement: 

Stone .—The stones are to be the best selected water or bank 
paving-stones, of a durable and uniform quality. 


79 


80 


HIGHWAY CONSTRUCTION. 


TYPES OF STONE PAVEMENTS 



VMM- 






FIG. 1. ROMAN. 



Fig. 2. COBBLESTONE. 



Fig. 3. BELGIAN BLOCK. 



// 'V/ V\\ v 

Fig. 4. EARLY GRANITE BLOCK. 









































































STONE PAVEMENTS. 


81 


Size of Stone .—No stone shall be less than four (4) inches nor 
more than eight (8) inches in any direction on the surface. No 
triangular or split stone will be allowed. All stones shall be set 
perpendicular and on their small ends, the large stones to be placed 
on the sides of the street, and the small ones in the center. 

Foundation and Laying .—The pavement shall be laid on a 
bed of good sharp sand or fine gravel, at least ten (10) inches in 
depth, except where clay or a similar substance is met with, when 
the sand must be eighteen (18) inches deep. The bed of sand or 
gravel shall be laid ready for the pavement at least thirty (30) feet 
in advance of the pavement. The stones after being set in position 
must be rammed with a heavy rammer until they are firmly settled 
in their beds. After the pavement is rammed a layer of sand or 
gravel two (2) inches thick is spread over it and left to work its 
way in between the stones. 

In consequence of the many defects of this class of paving its 
construction has been practically abandoned, but large areas still 
remain, which are being gradually removed. 

136. Belgian Block Pavement. —Cobblestones were displaced by 
pavements formed of small cubical blocks of stone. This type of 
pavement was first laid in Brussels, thence imported to Paris, and 
from there to the United States, where it has been widely known 
as the “ Belgian block” pavement. It has been largely used in New 
York City, Brooklyn, and neighboring towns, the material being 
trap-rock obtained from the Palisades on the Hudson River. 

137. The stones being of regular shape remain in place better 
than the cobblestones, but the cubical form (usually five inches) is 
a mistake. The foothold is bad, the stones wear round, and the 
number of joints is so great that ruts and hollows are quickly 
formed. This pavement offers less resistance to traction than 
cobblestones, but it is rough and noisy. 

138. Specification for Belgian Block Pavement.— The following 
is the common form of specifications for the Belgian block: 

Stone .—The stones are to be obtained from the trap or other 

durable rocks. 

Size of Stones .—Each block shall measure not less than five' 
(5) inches nor more than seven (7) inches in length ; nor less than 
five (5) inches nor more than six (6) inches in width; in depth not 
less than six (6) inches nor more than seven (<) inches, noi shall 






82 


HIGHWAY CONSTRUCTION. 


tlie difference between the base and the top surface of any block 
exceed one inch in either direction. 

139. The blocks are laid upon a foundation of sand six inches 
thick, in parallel courses, perpendicular to the axis of the street. 
When so laid the blocks are thoroughly rammed to the required 
grade and cross-section. No ramming should be done within 
twenty-five feet of the work that is being laid. After ramming the 
surface is covered with a coat of clean sand which is broomed into 
the joints. 

140. Granite Block Pavement.—The Belgian block has been 
gradually displaced by the introduction of rectangular blocks of 
granite. Blocks of comparatively large dimensions were at first 
employed. They were from 6 to 8 inches in width on the surface, 
by from 10 to 20 inches in length, with a depth of 9 inches. 
They were merely placed in rows on the subsoil, perfunctorily 
rammed, the joints filled with sand, and the street thrown open 
to traffic. The unequal settlement of the blocks, the insufficiency 
of the foothold, and the difficulty of cleansing them led to the 
gradual development of the latest type of stone-block pavements, 
which consists of narrow rectangular blocks of granite, properly 
proportioned, laid on an unyielding and impervious foundation, 
with the joints between the blocks filled with an impermeable 
cement. This type is practically a return to the system of the 
Itomans, but with blocks of lesser dimensions than they used. 

141. Experience has proved beyond doubt that this latter type 
of pavement is the most enduring and economical for roadways 
subjected to heavy and constant traffic. Its advantages are many, 
while its defects are few. 

♦ 

142. Advantages. 

(1) Adaptability to all grades. 

(2) Suits all classes of traffic. 

(3) Exceedingly durable. 

(4) Foothold, fair. 

(5) Requires but little repair. 

(6) Yields but little dust or mud. 

(7) Facility for cleansing, fair. 

143. Defects.—(1) Under certain conditions of the atmosphere 
its surface becomes greasy and slippery. 

(2) The incessant din and clatter occasioned by the movement 



STONE PAVEMENTS. 


S3 


IMPROVED GRANITE-BLOCK PAVEMENT. 


GUTTER FORMED OF 
ROWS OF BLOCKS 
*€ET LONGITUDINALLY. 

V777PI 



CURB 5"WIDE 
| AND 18" DEEP. 


Pig.5. CROSS SECTION. 




FIG. 7. LONGITUDINAL SECTION. 





















































































































84 


HIGHWAY CONSTRUCTION. 


of traffic over it is an intolerable nuisance, and it is claimed by 
many physicians that the noise injuriously affects the nerves and 
health of persons who are obliged to live or do business in the 
vicinity of streets so paved. 

(3) Horses constantly employed upon it soon suffer from the' 
continual jarring produced in their legs and hoofs, and quickly 
wear out. 

(4) The discomfort to persons riding over it is very great because 
of the continual jolting to which they are subjected. 

(5) If stones of an unsuitable quality are used, i.e., those that 
polish, the surface quickly becomes slippery and exceedingly unsafe- 
for travel. 

144. Quality of the Stone.—The harder and more durable rocks 
like basalt and true granite are unsuitable; they have the fault of 
wearing smooth and more or less spherical when subjected to heavy 
traffic, and under certain conditions of the weather they become 
greasy and slippery. 

145. The less durable rocks, such as syenite, the granites in 
which hornblende predominates, and the harder sandstones, are the 
most suitable; they do not polish and afford a good foothold for 
the horses. Where the harder and more durable rocks have been 
used, they have caused dissatisfaction, and have been removed before 
they had been down many years. 

146. Size and Shape of the Blocks.—The proper size of the blocks 
for paving purposes has been a subject of much discussion, and a 
great variety of forms and dimensions are to be found in all cities. 

For stability a certain proportion must exist between the depth, 
the length, and the breadth. The depth must be such that when the 
wheel of a loaded vehicle passes over one edge of its upper surface 
it will not tend to tip up. The resultant direction of the pressure 
of the load and adjoining blocks should always tend to depress the 
whole block vertically; where this does not happen the maintenance 
of a uniform surface is impossible. To fulfil this requirement it is 
not necessary to make the block more than seven (7) inches deep. 

147. Width of the Blocks.—The maximum width of the blocks 
is controlled by the size of horses’ hoofs. To afford good foothold to 
horses drawing heavy loads, it is necessary that the width of each 
block measured along the street shall be the least possible consistent 
with stability; if it is large, a horse drawing a heavy load attempt- 





STONE PAVEMENTS. 


85 


ing to find a joint slips back, and requires an exceptionally wide 
joint to pull him up. It is therefore desirable that the width of a 
block should not exceed three (3) inches, or that four taken at 
random and placed side by side will not measure more than fourteen 
(14) inches. 

148. Length of the Blocks. —The length measured across the 
street must be sufficient to break joints properly, for two or more 
joints in a line lead to the formation of grooves. For this purpose 
the length of the block should be not less than nine (9) inches nor 
more than twelve (12) inches. 

149. Form of the Blocks. —The blocks should be well squared 
and must not taper in any direction; sides and ends should be free 
from irregular projections. Blocks that taper from the surface 
downwards (wedge-shaped) should not be permitted in the work; 
but if any are allowed, they should be set with the widest side down. 

150. Manner of Laying the Blocks. —The blocks should belaid 
in parallel courses, with their longest side at right angles to the 
axis of the street, and the longitudinal joints broken by a lap of 
at least two inches (see Fig. G). The reason for this is to prevent 
the formation of longitudinal ruts, which would happen if the 
blocks were laid lengthwise. Laying the blocks obliquely and 
“herring-bone” fashion has been tried in several cities with the 
idea that the wear and formation of ruts would be reduced by 
having the vehicles cross the blocks diagonally. The method has 
failed to give satisfactory results; the wear was irregular and the 
foothold defective, the difficulty of construction was increased by 
reason of the labor required to form the triangular joints, and the 
method was wasteful of material. 

151. The gutters should be formed by three or more courses of 
block, laid with their length parallel to the curb. 

152. At junctions or intersections of streets the blocks should 
be laid diagonally from the centre, or “ herring-bone ” fashion, as 
shown in Fig. 7 a. The reason for this is (1) to prevent the traffic 
crossing the intersection from following the longitudinal joints 
and thus forming depressions and ruts; (2) laid in this manner 
they afford more secure foothold for horses turning the corners. 
The ends of the diagonal blocks where they abut against the 
straight blocks must be cut to the required bevel. The method of 
paving junctions shown in Fig. 7 b while extensively employed is 
erroneous for the above reasons. 



8G 


HIGHWAY CONSTRUCTION 


t 






Fig. 7a. intersection paved with granite blocks. 





































































STONE PAVEMENTS. 


87 



SECTION ON A, B, C, D. 



Fig. 7b.— INTERSECTION PAVED WITH GRANITE BLOCKS. 


153 . The blocks forming each course must be of the same depth, 
and no deviation greater than one quarter (±) of an inch should be 
permitted. The blocks should be assorted as they are delivered, 
and only those of corresponding depth and width should be used in 
the same course. The better method would be to accurately gauge the 
blocks at the quarry: the cost would be considerably less; it would 
also avoid the inconvenience to the public by the stopping of travel 
resulting from the rejection of defective material on the ground. 
This method would undoubtedly be preferable to the contractor, 
who would be saved the expense of handling unsatisfactory material, 
and it would also leave the inspectors free to pay more attention to 
the manner in which the work of paving is performed. 










































































































































































































88 


HIGHWAY CONSTRUCTION". 


The accurate gauging of the blocks is a matter of much im¬ 
portance. If good work is to be executed, the blocks when laid 
must be in parallel and even courses; and if the blocks be not ac¬ 
curately gauged to one uniform size, the result will be a badly paved 
street with the courses running unevenly. 

The cost of assorting the blocks into lots of uniform width, after 
delivery on the street, is far in excess of any additional price which 
would have to be paid for the accurate gauging at the quarry. 

154. Foundation. —The foundation of the blocks must be solid 
and unyielding, a bed of hydraulic cement concrete is the most 
suitable, the thickness of which must be regulated according to 
the traffic; the thickness, however, should not be less than four (4) 
inches and need not be more than nine (9) inches. A thickness 
of six (6) inches will sustain at raffic of GOO tons per foot of width. 

155. Cushion-coat. —Between the surface of the concrete and the 
base of the blocks there must be placed a cushion-coat formed of an 
incompressible but mobile material, the particles of which will 
readily adjust themselves to the irregularities of the base of the 
blocks and transfer the pressure of the traffic uniformly to the con¬ 
crete below. A layer of dry, clean sand f of an inch thick forms an 
excellent cushion-coat. Its particles must be of such fineness as will 
pass through a No. 8 screen; if coarse and containing pebbles, they 
will not adapt themselves to the irregularities of the base of the 
blocks, hence the blocks will be supported only at a few points and 
unequal settlement will take place when the pavement is subjected to 
the action of traffic. The sand must also be perfectly free from 
moisture, artificial heat must be used to dry it if necessary. This 
requirement is an absolute necessity. There should be no moisture 
below the blocks when laid, nor should water be allowed to penetrate 
below the blocks; if such happens, the effect of frost will be to up¬ 
heave the pavement and crack the concrete. 

Where the best is desired without regard to cost, a layer half 
an inch thick of asphaltic cement may be substituted for the sand 
with superior and very satisfactory results. 

156. Laying the Blocks. —The blocks should be laid stone to 
stone, so that the joint may be of the least possible width; wide 
joints cause increased wear and noise and do not increase the foot¬ 
hold. The courses should be commenced on each side and worked 
toward the middle, and the last stone should fit tightly. 




STONE PAVEMENTS. 


89 


157. Ramming.—After the blocks have been set they should be 
well rammed down, and the stones which sink below the general 
level should be taken up and replaced with a deeper stone or 
brought to level by increasing the sand-bedding. 

158. The practice of workmen is invariably to use the rammer 
so as to secure a fair surface. This is not the result intended to be 
secured, but to bring each block to an unyielding bearing. The 
result of such a surfacing process is to produce an unsightly and 
uneven roadway when the pressure of traffic is brought upon it. 
The rammer used should not weigh less than fifty pounds and have 
a diameter of not less than three inches. 

159. Joint - filling. — All stone - block pavements depend for 
their water-proof qualities upon the character of the joint-filling. 
Joints filled with sand and gravel are of course pervious. A grout of 
lime or cement mortar does not make a permanently water-tight 
joint; it becomes disintegated under the vibration of the traffic. An 
impervious joint can only be made by employing a filling made 
from bituminous or asphaltic material; this renders the pavement 
more impervious to moisture, makes it less noisy, and adds con¬ 
siderably to its strength. 

160. Bituminous Cement for Joint-filling.—The bituminous ma¬ 
terials employed are (1) the tar produced in t?he manufacture of 
gas, which, when redistilled, is called distillate , and is numbered 
1. 2, 3, 4, etc., according to its density; this material under the 
name of paving -pitch is extensively used both alone and in com¬ 
bination with other bituminous substances; (2) combinations of 
gas- or coal-tar with refined asphaltum; (3) mixtures of refined 
asphaltum, creosote, and coal-tar. 

The formula for the bituminous joint-filling used in New York 


City is: 

Refined Trinidad asphaltum. 20 parts 

No. 4 coal-tar distillate. 100 

Residuum of petroleum. 3 “ 


In Washington, D, C., coal-tar distillate No. G is used alone. 

In Europe a bituminous cement much used is composed of coal- 
tar, asphaltum, gas-tar, and creosote oil, in the proportion of 100 
pounds of asphaltum to 4 gallons of tar and 1 gallon of creosote. 
These proportions are varied somewhat, according to the quality 
of the asphaltum employed. The mixture is melted, and boiled from 






HIGHWAY CONSTRUCTION. 


<J() 


one to two hours in a suitable boiler, then poured into the joints 
in a boiling state. This mixture is impervious to moisture, and 
possesses a degree of elasticity sufficient to prevent it from cracking. 

161. The mode of applying the bituminous cement is as follows: 
After the blocks are rammed the joints are filled to a depth of about 
two inches with clean gravel heated to a temperature of about 250° 
F., then the hot cement is poured in until it forms a layer of about 
one inch on top of the gravel, then more gravel is filled in to a depth 
of about two inches, then cement is poured in until it appears on 
top of the gravel, then more gravel is added until it reaches to 
within half an inch of the top of the blocks; this remaining half 
inch is filled with the cement, and then fine gravel or sand is 
sprinkled over the joints. 

In some cases the joints are first filled with the heated gravel, 
then the cement poured in until the sand beneath and the gravel 
between the blocks will absorb no more and the joints are filled 
flush with the top of the pavement. This method is open to ob¬ 
jection, for if the gravel is not sufficiently hot the cement will be 
chilled, and will not flow to the bottom of the joint, but instead 
will form a thin layer near the surface, which, under the action of 
frost and the vibration of traffic, will be quickly cracked and broken 
up, the gravel will settle and the blocks will be jarred loose, and 
the surface of the pavement will become a series of ridges and hol¬ 
lows. 

The quantity of cement required per square yard of pavement 
will vary according to the shape of the blocks, width of the joints, 
and depth of the sand-bed; with well-shaped blocks, close joints, 
and one half inch sand-bed the quantity will vary from 3^ to 5 
gallons; with ill-shaped blocks, wide joints, and heavy sand-bed 10 
to 12 gallons would not be an excessive amount to use to secure 
the result obtained by employing well-shaped blocks and close 
joints. 

The cost of paving-pitch is variable; it ranges from six to ten 
cents per gallon. 

A joint-filling known as “ Murphy's Grout Filling” has been 
and is extensively used in the Central States. This filling is com¬ 
posed of Portland cement, iron-slag, and sand. It is said to be 
waterproof, durable, and cheap. It can be used with equal advan¬ 
tage for block, brick, cobblestone, and macadam pavements. 



STONE PAVEMENTS. 


91 


In manner of application it differs but little from that of the 
bituminous cement. It is mixed in a portable box, and when of a 
good flowing (but not liquid) consistency it is thrown upon the 
pavement with shovels and swept into the joints with steel brooms, 
and after forty-eight hours it is set and the pavement is ready for 
traffic. 

162. Sandstone-block Pavements.— Block pavements formed of 
Medina and Berea sandstones are used in several of the Lake cities. 
While not as lasting as granite, the sandstone is very durable, is 
less noisy, and does not become polished or slippery under traffic, 
wears evenly, and is adapted to all classes of traffic. 

163. The best examples of this kind of pavement are found in 
Buffalo, K. Y., where two classes are used. For first class the 
specifications call for a foundation of six inches of concrete with a 
three-inch cushion of sand. The blocks are of dressed stone, four 
inches wide, seven inches deep, and not less than eight inches long. 
The joints are filled with bituminous cement. For the second 
class the blocks are of irregular size laid on a foundation of ten to 
eighteen inches of sand, depending upon the character of the sub¬ 
soil, the joints are filled with sand.” 

164. The cost of first-class Medina in Buffalo is 84 per square 
yard; Cleveland, 83.50; Columbus, with a 10-inch broken-stone 
foundation, 83.25. Second-class average $1.75, and with asphalt 
filling cost 36 cents per yard more. 

165. Limestone-block Pavements.— Limestone block was tried 
in Kansas City on a concrete foundation, but being set on edge it 
wore unevenly, and in a year or two was shivered and split by the 
frost. This is the universal experience of all cities using limestone 
blocks. 

166. Pavements on Steep Grades.— Stone blocks may be em¬ 
ployed on all practicable' grades, but on grades exceeding 10# 
cobblestones afford a better foothold than blocks. The cobble¬ 
stones should be of a uniform length, the length being at least 
twice the breadth, say stones 6 inches long and 2£ to 3 inches in 
diameter. These should be - set on a concrete foundation, laid 
stone to stone, and the interstices filled with cement grout or 
bituminous cement; or a bituminous concrete foundation may 
be employed and the interstices between the stones filled with 



92 


HIGHWAY CONSTRUCTION. 


STONE PAVEMENTS ON GRADES. 



Fig. 8. COBBLE ON CONCRETE. 



Fig. 9. GRANITE BLOCKS—STEPPED. 



Fig. 1 0. 


GRANITE BLOCKS—WIDE JOINTS. 






















































STON E PAVEMENTS. 


93 


asphaltic paving-cement. Should stone blocks be preferred, they 
must be laid, when the grade exceeds 5 fo, with a serrated surface by 
either of the methods shown in Figs. 9 and 10. The method 
shown in Fig. 9 consists in slightly tilting the blocks on their bed 
so as to form a series of ledges or steps, against which the horses’ 
feet being planted, a secure foothold is obtained. The method 
shown in Fig. 10 consist in placing between the rows of stones a 
course of slate, or strips of creosoted wood, rather less than one 
inch in thickness and about an inch less in depth than the blocks ; 
or the blocks may he spaced about one inch apart, and the joints 
filled with a grout composed of gravel and cement. The pebbles 
of the gravel should vary in size between one quarter and three 
quarters of an inch. 

167. Durability of Granite Blocks. —The average life or dura¬ 
bility of granite blocks under heavy traffic may be taken at fifteen 
years; but since the nature of the traffic, the state of cleanliness 
and other conditions must be taken into account when inquiring 
into the durability, it follows that in no two streets is the endur¬ 
ance or the cost the same, and the difference between the highest 
and the lowest period of endurance and amount of cost is very 
considerable. The practice followed almost uniformly in the 
English cities is to remove the worn blocks, re-dress them and 
relay them in other and secondary thoroughfares. Thus the 
duration or life of the blocks may be doubled or more than 
doubled. Indeed, with the exception of the portion worn off by 
the friction of the traffic, not a fragment of granite paving may be 
said to be lost. After passing its first years in a leading thorough¬ 
fare it goes into a secondary thoroughfare until completely worn 
down and rounded, and will even then command a price of from 
30 to 60 cents per square yard. Not even a fragment that is 
knocked off the component stones when undergoing the operation 
of being dressed into shape is lost, as it is made available either for 
macadamizing or for concrete to form the foundation of other 
pavements. “ In truth granite can only be said to be worn out 
when it has been broken up for macadamization and then crushed 
into powder b} 7 the vehicles.” 

168. Wear of Granite Blocks. —Stones from different quarries 
and even from the same quarry will show considerable variation in 
the amount worn away in a given time under exactly similar 
conditions. Therefore no statement of wear can be given which 








94 


HIGHWAY CONSTRUCTION 


will be applicable to all varieties of stones. On London bridge, 
which has a traffic of over 15,000 vehicles in 12 hours, the wear 
of granite blocks has been found to be at the rate of .222 inch per 
year, or the number of years required to wear away one inch is 
four and one half. 


TABLE XXY. 

Wear and Duration of Aberdeen Granite Pavements in the City of 
London. Blocks 3 inches wide, 9 inches deep. 

rtical Wear. Duration. 
Inches. Years. 

iV i 

2 15 

2 20 

4 35 

5 
9 

In Liverpool, under a traffic of 216,570 tons per yard of width 
pei annum, the wear was not measurable. 

169, Cost of Maintaining Granite-block Pavements. —As to the 
durability and cost of maintaining granite-block pavements in 
America no satisfactory statistics can be obtained. 

The annual cost of maintenance in London varies from six to 
nineteen cents per square yard, depending upon the traffic. In 
Liverpool repairing costs four cents per annum, and cleaning and 
sprinkling fourteen cents. In London the cost of maintenance, 
including interest, etc., on first cost is from 25 to 69 cents per 
square yard per annum. In St. Louis, Mo., maintenance costs 
from % to 2£ cents per annum. 

The average cost of maintaining granite-block pavements in 
the United States, irrespective of traffic tonnage, and exclusive 
of cleaning and sprinkling, appears to be about 1^ cents per square 
yard per annum. 

170. Method of Paying for Granite-block Pavements. —The 

present system of paying for granite-block paving is erroneous. 
The contractor buys his blocks at so much a thousand, and sells 
them at so much a square yard laid; thus it is his interest to have 
as few blocks to the square yard as possible and joints as large as he 
can. Or he may purchase them from the stone man at so much a 
square yard: in this case the stone man is interested in having as 


Aberdeen Granite Pavements. 

Vertical wear per 100 vehicles iu 12 hours, 

per foot of width per year. 

Total vertical wear in principal streets. 

Total additional wear in minor streets. 

Total vertical wear when laid aside. 

Remaining depth when laid aside. 

Depth of new blocks. 











STOKE PAVEMENTS. 


95 


few blocks as possible; as is also the contractor, for the fewer 
blocks to be laid to the yard the more yards of paving will the 
pavior lay in a day, thus increasing the profits of the contractor. 
In some cases the pavior is paid by the square yard of paving; then 
it becomes his interest to have as few blocks to handle as possible 
and as wide joints as he may, thus increasing the number of square 
yards of paving he can lay in a day, and thereby increasing his wages. 
No matter how looked at, all parties concerned in furnishing and 
laying the blocks are deeply interested in having as few blocks and 
as wide joints as possible to the square yard. As both of these are 
serious defects, the temptation to adopt them should be removed. 
The number of blocks to be laid per square yard should be clearly 
stated in the specifications ; a sum should also be designated to be 
deducted from the estimate, by way of a penalty or forfeit, for every 
block less that is used than the number called for. As the labor 
expended in ascertaining the number of blocks laid to each square 
yard would be very great, it would be better to specify, as is the 
custom in Liverpool, that four courses of block shall not measure 
more than fourteen (14) inches, hinder this rule the number of 
blocks laid can be very quickly determined by measuring any four 
courses at random over the length of the street. 

City Engineer Horace Andrews of Albany has introduced with 
considerable success a reform iu the manner of payiug for granite 
block pavements. 

The following unusual clauses are taken from his specifications, 
under which a large area of granite-block pavement has been laid: 

“ It is expressly understood and agreed, by and between the 
parties hereto, that the sum paid per square yard for granite block 
pavement shall be ascertained and fixed as follows—namely: The 
number of granite blocks per square yard, upon which the bid of 
the proposer is based, shall be 24. The actual average number of 
blocks laid per square yard by the contractor on the whole street 
shall be determined as follows: The City Engineer shall, from time 
to time, during the progress of the work, measure the width of the 
blocks as laid (by measuring the aggregate width of 50 to 100 
courses, from this deducing the average width), which he shall 
combine with the average length of block as laid (hereby fixed and 
determined as 12J inches), for the purpose of computing the 
number of blocks laid per square yard. 





9G 


HIGHWAY CONSTRUCTION - . 


“ For each block, or fractional part thereof, that the average 
number laid per square yard shall exceed 24 there shall be added 
to the contractor’s bid per square yard an amount computed at the 
rate of 94 cents per block. For each block, or fractional part 
thereof, that the average number laid per square yard shall fall 
short of 24, there shall be deducted from the contractor’s bid per 
square yard an amount computed at the rate of 94 cents per block. 

“ In order to lay 24 to the square yard, the width of five courses, 
including the joints between the stones, should not exceed 22 
inches.” 

The number of blocks specified per square yard ditfered on the 
individual streets; otherwise there were few changes in the above 
clauses. 

The results obtained by the use of these clauses in the specifica¬ 
tions during the last two jears are indicated in the following 


TABLE 

Showing Operation of Specifications regarding Joints in Granite 

Pavement in 1890 and 1891. 



Area in 
Square 
Yards. 

Width of 
Five Courses 
as laid. 
Inches. 

Number of 
Blocks laid 
per Square 
Yard. 

Excess or 
Deficiency. 

Contractor’s 

Gain. 

Contractor’s 

Loss. 

1 

3,624 

23.38 

22.62 

+ 0.12 

$43.40 


2 

1,588 

23.13 

22.87 

+ 0.37 

55.56 


3 

879 

23.50 

22.50 

0.00 



4 

11,202 

23.28 

22.72 

+ 0.22 

238.61 


5 

3.918 

22.99 

23.01 

- 1.99 


$740.09' 

6 

15,218 

23.86 

22.17 

- 0.33 


471.75 

7 

1.641 

24.57 

21.53 

- 0.93 


150.93 

8 

2.363 

21.69 

24.39 

+ 0.39 

87.44 


9 

2,146 

22.06 

23.98 

- 0.02 


4.29 

10 

2,679 

24.18 

21.88 

- 0.62 


158.08 

11 

5,120 

24.91 

21.23 

- 1.27 


614.38 

12 

2,846 

23.31 

22.70 

- 1.30 


350.01 


Note.— The specified number of blocks per square yard varied on different 
streets. It can be easily found from columns 4 and 5. 


From an inspection of this table it is evident that close paving 
can be secured. Mr. Andrews believes that it might be more 
beneficial if the amount of deduction for non-fulfilment were 
increased, to guard against the contingency of wide blocks being 






















STONE PAVEMENTS. 


97 


obtainable at so low a rate as to make it profitable for a contractor 
to use them notwithstanding the deduction from his contract price 
per square yard. 

171. Number of Granite Blocks per Square Yard. —Table XXVI 
shows the average number of granite blocks of different sizes 


Width. 

Length. 

Average Number of 
Blocks per sq. yd. 
Exclusive of Joints. 

Number of Square Yards 1 ton 
will cover at a depth of 

7 inches. 

9 inches. 

3 inches 

7 inches 

62 

2.50 

2.00 

3 “ 

9 “ 

48 

< < 

4 ( 

3 “ 

10 “ 

4° 

«c 

C 

3 “ 

12 “ 

36 

if 

if 

31 “ 

7 “ 

53 

i < 

( i 

3* “ 

9 “ 

41 

<( 

l« 

31 “ 

10 “ 

37 

< i 

a 

3* “ 

12 “ 

30 

€i 

a 


per square yard, and the average number of square yards that one 
ton of granite will cover, but these quantities will vary with the 
specific gravity of the stone employed. 

172. Cost of Construction. —The cost of granite-block pavements 
varies greatly; it is materially affected by the weight of the blocks 
when their transportation for any considerable distance has to be 
taken into account, by the character of the foundation and kind of 
joint-filling, and frequently by the condition of the labor market, 
demand, etc. 

Tables XXVII, XXVIII, XXIX, and XXX show the extent 
and cost of granite-block, trap-block, sandstone-block, and cobble¬ 
stone pavements in some of the principal cities of the United States 
in 1890. 


















98 


HIGHWAY CONSTRUCTION. 


TABLE XXVII. 

Extent and Cost of Granite-block Pavements in Several of the 
Principal Cities of the United States in 1890. 


Cities. 


New York, N. Y. 

Boston, Mass. 

Brooklyn, N. Y... 

St. Louis, Mo. 

Atlanta, Ga... 

Cincinnati, Ohio. 

Washington, D. C. 

Chicago, Ill.. 

Richmond, Va.. 

Albany, N. Y.. 

Newark, N. J. 

Lowell, Mass. 

Providence, R. I. 

Troy, N. Y.. 

Milwaukee, Wis. 

Worcester, Mass. 

Omaha, Neb. 

New Haven, Coun. 

Minneapolis, Minn. 

Cambridge, Mass. 

Trenton, N. J. 

Los Angeles, Cal. 

Wilmington, N. C. 

Nashville, Tenn. 

Waterbury, Conn. 

St. Paul, Minn. 

*Toronto, Can. 

^London (City), Eng.... 

“ (Vestries), Eng 

^Birmingham, Eng. 

^Liverpool, “ . 


Extent. Cost of Construction 

Miles. per square yard. 


140.00 

62.00 

55.30 

43.71 

33.00 

30.00 

23.20 

20.48 

16.58 

16.39 

13.36 

10.00 

9.20 

9.12 

7.50 
7.00 
6.00 

4.25 
4.16 
3.63 

3.50 

1.50 

1.25 
1.25 
1.10 
0.39 

29.00 ) 
251.00 f 
26.00 


12.50 to $4.50 f 


2.75 “ 

2.75 

3.52 

1.50 

4.25 

4.00 f 

2.85 to 

3.13 

2.48 

3.47 f 

2.78 to 
2.75 

3.45 f 

1.80 to 

2.25 

2.50 “ 

4.00 f 

2.15 to 
2.25 
1.98 
2.50 

2.45 

1.80 to 
2.20 
3.00 
2.52 
2.50 
3.15 

2.57 

2.75 to 
2.10 

2.95 

3.00 to 

3.85 f 

3.60 “ 

2.88 

3.75 

4.08f 


* Foreign cities for comparison. 

f Concrete foundation. Where not noted the foundation is either sand or 
gravel. 















































STONE PAVEMENTS. 


99 


TABLE XXVIII. 


Extent and Cost of Belgian Block (Trap) Pavements in some of the 
Principal Cities of the United States in 1890. 


Cities. 


Extent. Cost of Construction 

Miles. per square yard. 


New York. N. Y 
Philadelphia, Pa. 
Brooklyn, N. Y., 
Paterson, N. J. .. 
Camden, N. J .. 
Albany, N. Y... 
Kingston, N. Y., 


199.07 

$2.50 

119.60 

2.37 

22.41 


2.75 

1.80 to $2.14 

2.08 

2.00 

1.42 

2.60 

1.90 



TABLE XXIX. 


Extent and Cost of Sandstone-block Pavements in some of the 
Principal Cities of the United States in 1890. 


Cities. 

Extent. 

Miles. 

Cost of Construction 
per square yard. 

Buffalo N" V . 

138.00 

$2.00 

1.34 

Toledo Ohio. 

17.48 

T?nflip«tpr IV Y . 

16.50 

2.25 

O m «hn TVJ pIi. ...... 

11.00 

1.98 

Tt!ri'p> Pa . 

6.81 

2.78 

"Elmira "N" "YY , . f . 

5.00 

TTtien NY . 

4.63 


Tiorknort N Y T .. 

4.00 


fttrvnnncp "N" ^ ... 

3.40 

1.80 to $3.69* 
2.98 “ 3.94* 





* Concrete foundation. 








































100 


HIGHWAY CONSTRUCTION. 


TABLE XXX. 

Extent and Cost of Cobblestone Pavements in some of the Prin¬ 
cipal Cities of the United States in 1890. 


Cities. 

Extent. 

Miles. 

Cost of Construction 
per square yard. 

Philadelphia Pa. 

490.60 


Brooklvn X Y . 

280.38 


A lhn.iiy X Y... 

35.81 


Milwaukee Wis.. 

35.00 

$0.85 

New Orleans La.•. 

33.00 

Newark N .1 . 

26.18 


Ganirlen N. .T.. 

16.93 

0.65 to 1.25 

Tietrnit Minli. 

16.07 

1.50 

ftelieneotarl v X Y._ . . 

15 00 

Wa.sliin cton . O 0 . 

12.00 


Utica X Y. 

10.71 


Providence. R T. .. 

10.30 

1.25 

.Tersev Oitv X .1. 

10.00 

Host,on Mass. .. 

8.00 


Cumberland. Md. 

7.00 


Trov X Y. 

5 50 


Hew York X. Y. 

5.13 


Toledo Ohio. 

4.62 


Trenton X J. 

4.50 

0.65 

Poncrhkeensie. X. Y.. 

4.25 

Syracuse N. Y... 

1.54 


Grand Banids Mich... 

1.33 

0.40 

Osweiro X. Y... 

1.30 

Xew Haven, Conn. 

0.12 

0.75 



173. Heads of Specifications for Granite-block Pavement. 

(1) Preparation of Roadbed. 

(2) Foundation. 

(3) Quality of the Blocks .—The paving-blocks shall be of 

syenite or granite from or other approved quarries. All 

the blocks shall be of the same quality as to hardness, color, and 
grain; no outcrop, soft, brittle, or laminated stone will be accepted. 
’When stone is obtained from more than one quarry, that from each 
quarry shall be piled and laid in separate sections of the work. In 
no case shall the stones from different quarries be mixed. 

(4) Dressing .—The blocks are to be split and dressed so as to 
present regular and true surfaces on all sides, with straight edges 
on top, bottom, and sides. All sides of the block must be free from 
depressions or projections, and all blocks whose faces vary more 
than one half inch from rectangular shape will be rejected. 









































STONE PAVEMENTS. 


101 


(5) Size of the Blochs. —The blocks shall measure 3J inches 
wide, 7 inches deep, and may vary between 9 and 12 inches in 
length. In no case will any variation in the width be permitted. 
In some cases, as paving around man-hole heads, etc., blocks of 
lesser depth may be required, and will be used as directed by the 
engineer. 

(6) Inspection and Culling. —The blocks will be inspected after 
they are brought on the line of the work, and all blocks which in 
quality and dimensions do not conform strictly to these specifica¬ 
tions will be rejected, and must be immediately removed from the 
line of the work. The contractor must furnish such laborers as 
may be necessary to aid the inspector in the examination and the 
culling of the blocks; and in case the contractor neglect or refuse 
to furnish said laborers, such laborers as in the opinion of the 

may be necessary will be employed by said , 

and the expense thus incurred by will be deducted and 

paid out of any money then due or which may thereafter become 
due to said contractor under the contract to which these specifica¬ 
tions refer. 

(7) Cushion-coat.— On the concrete foundation a layer of clean 
sharp sand free from moisture will be evenly spread to a depth of 
one half inch. The sand if not dry must be made so by the appli¬ 
cation of artificial heat, in such apparatus as may be suitable for 
the purpose and approved of by the engineer. 

(8) Laying the Blochs.— The blocks will be bedded in the sand, 
laid stone to stone in parallel courses at right angles to the axis of 
the street (except at intersecting streets, where they will be laid on 
the diagonal as shown on the plans). Each course shall consist of 
blocks of uniform width and depth. The blocks shall be so laid 
that the longitudinal joints shall be broken by a lap of at least two 

inches. 

(9) Jointing.— After the blocks are so laid, the joints between 
them shall be filled to a depth of two inches with clean, dry gravel, 
then rammed to an unyielding bearing with a hand rammer weigh¬ 
ing not less than fifty pounds. All blocks which sink below the 
general level must be removed and replaced with blocks of greater 
depth. After the blocks are rammed the paving cement will be 
poured into the joints, to a depth of two inches; the joints will 
then be filled flush with gravel and the cement poured in until the 



102 


HIGHWAY CONSTRUCTION. 


joints are filled and will absorb no more. Dry sand will then be 
poured along the joints and spread over the entire pavement. The 
quantity of paving cement required per square yard of pavement 
will not be less than four gallons. This quantity must be brought 
upon the ground, and whatever may remain after the completion 
of the work will be the property of the city. Any wastage of paving 
cement by pouring over the surface instead of between the blocks 
must be covered with a sufficient quantity of fine dry gravel to 
absorb it. The amount so wasted will be estimated, and the quan¬ 
tity so estimated must be replaced by the contractor at his expense. 

(10) Composition of Paving Cement. —The paving cement will 
be composed of the residuum obtained from the direct distillation of 
coal-tar and creosote oil, in the proportion of fifty gallons of oil to 
one ton of residuum; the two ingredients will be melted together 
in suitable iron boilers having a capacity of not less than one ton. 
It shall be poured into the joints while in a boiling state. 

(11) Quality of the Gravel.— The gravel used for filling the 
joints shall be free from sand, clay, or other objectionable substances; 
it shall be of such size as will pass entirely through a sieve of three 
quarters of an inch mesh and be retained by a quarter-inch mesh. 

(12) Materials to be Kept Dry. —The stone for the pavement, 
the sand for the bed, and the gravel for the joints shall each and 
severally be laid only when dry and free from moisture. After 
being laid the contractor shall jwotect them from the weather until 
the joints have been filled with the paving cement; should they 
become moist from any cause previous to filling the joints with the 
said cement, the contractor shall at his own expense remove that 
portion of the work so moistened and replace and- complete the 
same with dry materials. 

(13) Laying Granite Blochs adjacent to Railway Tracks, etc. 
Between, and one foot outside of railroad tracks, over vaults, 
around sewer-manhole frames, and in such other places as the 
engineer may designate, the contractor shall furnish and use for 
the pavement blocks of such lesser depths as the engineer may 
direct. The general dimensions of such blocks on the top surface 
shall be the same as for the main pavement. 

(14) The number of blocks laid per square yard shall be thirty, 
so laid that ten courses measured lengthwise of the street shall 
measure not more than 35 inches. The actual average number of 



STONE PAVEMENTS. 


103 


granite blocks laid per square yard shall be ascertained by the city 
engineer; and for each block, or fractional part thereof, that the 
average number of blocks laid per square yard shall fall short of 
thirty there shall be deducted from the contractor’s bid price an 
amount computed at cents for each block less than thirty. 

(15) Interpretation of specifications. 

(16) Omissions in specifications. 

(17) Engineer defined. 

(18) Contractor defined. 

(19) Notice to contractors, how served. 

(20) Preservation of engineer’s marks, etc. 

(21) Dismissal of incompetent persons. 

(22) Quality of materials. 

(23) Samples. 

(24) Inspectors. 

(25) Defective work, responsibility for. 

(26) Measurements. 

(27) Partial payments. 

(28) Commencement of work. 

(29) Time of completion. 

(30) Forfeiture of contract. 

(31) Damages for non-completion. 

(32) Evidence of the payment of claims. 

(33) Protection of persons and property. 

(34) Bond for faithful performance of work. 

(35) Power to suspend Avork. 

(36) Right to construct sewers, etc. 

(37) Loss and damage. 

(38) Old materials, disposal of. 

(39) Cleaning up. 

(40) Personal attention of contractor. 

(41) Payment of workmen. 

(42) Prices. 

(43) Security retained for repairs. 

(44) Payment, when made. Final acceptance. 



CHAPTER IV. 


WOOD PAVEMENTS. 

174. Wood Pavements.—Pavements formed of wood have been 
extensively employed both in Europe and the United States, but 
with widely differing results in the two countries. The experience in 
the United States has been, with but few exceptions, unsatisfactory, 
while in Europe, especially in the city of London, wood pavements 
have proved very successful and are quite popular. 

175. The success of wood pavements in Europe is due to the 
fact that more care is exercised in their construction and mainte¬ 
nance. There, a solid concrete foundation, well-seasoned wood, 
and water-proof cement filling for the joints are employed, with 
constant and careful attention to keep them in repair. 

176. The unsatisfactory results obtained in the United States 
are attributable, first, to the methods of construction; second, to 
the employment of green wood; and third, to the lack of careful 
maintenance. 

177. The advantages of wood pavement may be stated as 
follows: 

(1) It affords good foothold for horses. 

(2) It offers less resistance to traction than stone and slightly 
more than asphalt. 

(3) It suits all classes of traffic. 

(4) It may be used on grades up to five per cent. 

(5) It is moderately durable. 

(6) It yields no mud when laid upon an impervious foundation. 

(7) It yields but little dust. 

(8) It is moderate in first cost. 

(9) It is not disagreeably noisy. 

178. The principal objections to wood pavement are: 

(1) It is difficult to cleanse. 

(2) Under certain conditions of the atmosphere it becomes 
greasy and very unsafe for horses. 


104 


WOOD PAVEMENTS. 


105 


(3) It is not easy to open for the purpose of gaining access to 
underground pipes, and rather a large surface has to be removed for 
this purpose, and it has to be left a little time after being repaired 
before traffic is again allowed upon it. 

(4) It is absorbent of moisture. 

(5) It is claimed by many that wood pavements are unhealthy. 

179. Objections to Wooden Pavements on Hygienic Grounds.— 

Dr. 0. W. Wight, Health Officer of Detroit, in a report to the City 
Council, says: 

“ On sanitary grounds, therefore, I must earnestly protest against 
the use of wooden-block pavements. Such blocks, laid endwise, 
not only absorb water which dissolves out the albuminoid matter 
that acts as a putrefactive leaven, but also absorbs an infusion of 
horse-manure and a great quantity of horse-urine dropped in the 
street. The lower end of the blocks, resting on boards, clay, or 
sand, soon becomes covered with an abundant fungoid growth, thor¬ 
oughly saturated with albuminous extract and the excreta of ani¬ 
mals in a liquid putrescible form. These wooden pavements undergo 
a decomposition in the warm season, and add to the unwholesome¬ 
ness of the city. The street, in fact, might as well be covered a 
foot deep with rotting barnyard manure, so far as unwholesomeness 
is concerned. Moreover, the interstices between the blocks and the 
perforation of decay allow the foul liquids of the surface to flow 
through, supersaturating the earth beneath, and constantly adding 
to the putrefying mass.” 

M. Fonssagrivs, Professor of Hygiene at Montpellier, France, 
objects to wooden pavements because they “ consist of a porous 
substance capable of absorbing organic matter and by its own de¬ 
composition giving rise to noxious miasma, which, proceeding fiom 
so large a surface, cannot be regarded as insignificant. I am con¬ 
vinced that a city with a damp climate, paved entirely with wood, 
would become a city of marsh-fever.” 

Professor Brewer, of Yale College, says that “even in the free 
air and full sunlight, along with the putrescence a white fungous 
growth begins on the surface of the wood, which rapidly becomes 
slimy. This forms much more rapidly on the ends of the grain of 
the wood than on the radial or tangential sides. The fungous growth 
goes on, modified, of course, by the temperature and the degree of 
concentration, and it continues for an unknown peiiod, oi until the 




106 


HIGHWAY CONSTRUCTION. 


decay lias become complete. Heartwood and sapwood act essen¬ 
tially alike in this matter; the difference is one of degree rather 
than character/’ 

The following comments are from the report of a Board 
appointed by the Legislature of New South Wales to inquire into the 
alleged deleterious effects of wood pavement supon the public health. 

“ The Board examined specimens of wood pavement as laid in the 
city of Sydney, taking up blocks at different points. In all cases 
the concrete bed underneath was moist; in three cases a large 
amount of slimy mud was found giving off an ammoniacal odor. 
In all these the joints and blocks appeared to be uninjured. The 
blocks were chemically examined to determine whether they had 
absorbed organic matter, with the result that some were found 
impregnated with filth to the very centre, while others were com¬ 
paratively free from it. 

“ The Board comes to the conclusion that wood is a material 
which cannot safely be used for paving unless it can be rendered 
absolutely,impermeable to moisture, and so laid that while the 
entrance of water between the blocks is rendered impossible, the 
separation of the fibres at the surface by the concussion of traffic is 
also effectually prevented. These conditions have nowhere, to the 
knowledge of your Board, been fulfilled. 

“ So far as the careful researches of your Board go, the porous, 
absorbent, and destructible nature of wood must, in its opinion, be 
declared to be irremediable by any process at present known; nor, 
were any such process discovered, would it be effectual unless it 
were supplemented by another which should prevent fraying of the 
fibres. Still less can the defects of wood be considered to be of less 
consequence than the defects of other kinds of material. 

“ In this city it may perhaps be considered that an amount of 
wood has not yet been laid sufficient to affect the public health 
whatever its condition within reasonable limits may be; and upon 
this ground your Board does not recommend that the present pav¬ 
ing should be removed, but that the Board of Health should be 
empowered to examine it, and to report upon it, from time to time, 
with a view of ascertaining its behavior under longer exposure to 
weather and traffic than it has yet had, and that it should be no 
longer watered, but cleansed by sweeping at least twice a day (the 
sweeping to be done at right angles to the direction of the street, or 




WOOD PAVEMENTS. 


107 


parallel to the courses, so that the latter may be cleared out by the 
broom), in order that destructive dampness and penetration of dis¬ 
solved organic matter may be reduced as much as possible. But the 
presumption is, upon the evidence here adduced, that in this climate 
the results alluded to would ensue if the extent of surface were 
sufficiently enlarged or fouling and decay sufficiently extensive. 
Your Board therefore recommends that the paving of the streets of 
this city with wood should be discontinued, and desires to add that 
this recommendation is extended to apply not to the particular mode 
of construction here adopted alone, but to the material itself, and to 
every known method of construction.” 

180. Opinion of Col. Haywood, Engineer of the City of London.— 
“ It has been said that wood pavements at times smell offensively 
and may be unhealthy; but although some city streets have been 
paved with wood for thirty years, no complaints that I am aware 
of have been made to the commission on this head, and the in¬ 
habitants at all times have not only expressed great anxiety lest the 
wood should be replaced by other materials, but have subscribed 
toward the cost of its renewal. ... I have at times noticed 
offensive emanations from it near cab-stands, but am unable to find 
further evidence of its unhealthiness. These remarks must be held 
to apply only to public streets open to the sun, air, and traffic; in 
confined places and under some conditions wood might be objec¬ 
tionable. I have seen it decaying in confined places without 
traffic.” 

181. Wood Pavements and Death-rate.— A comparison of the 
death rate in cities using wood pavements with that in cities where 
little or no wood is employed seems to show that wood pavements 
do not cause an increase in the death-rate. 


Death-rate 
per 1000. 

- City. 

Percentage of 
Wood Pavements. 

17.48 

Chicago 

80 

25.19 

New York 

0 

23.31 

Boston 

0 

19.74 

Philadelphia 

0 

14.70 

Detroit 

91 

16.90 

Milwaukee 

48 

23.70 

Nashville 

0 

19.87 

Atlanta 

0 

9.17 

Duluth 

95 
















108 


HIGHWAY CONSTRUCTION. 



Fig. 1 2.—Section showing Joint Filling. 



Showing Arrangement of Blocks at Street Junctions. A B shows 
the Line of Travel in Turning Corners. 






















































































WOOD PAVEMENTS. 


109 


182. Variety of Systems. —Since the introduction of wood for 
paving, upwards of forty patented systems of construction have been 
experimented with. The difference between these systems consisted 
in the shape of the blocks and the treatment of the wood with 
chemicals. The shape given to the block has been very varied; 
round, square, rectangular, oblique, hexagonal, octagonal, and many 
complicated forms and interlocking devices have been tried. But 
experience has demonstrated that with a solid foundation there is 
no reason for complicated shapes or interlocking contrivances; and 
wood pavements in their modern form consist of either rectangular 
or cylindrical blocks set with the fibre of the wood vertical, with the 
joints between the blocks as narrow as possible and filled with a 
water-proof cement. 

The rectangular blocks are prepared by cutting with circular 
saws blocks of the required depth from planks 3 inches thick by 9 
or 12 inches wide. 

The cylindrical blocks are prepared by sawing from round logs 
pieces of the required length, usually 6 inches. These 6-inch pieces 
are passed through cylinders furnished with steel knives that remove 
the bark and sap-wood, and leave the blocks perfectly round and 
free from all unevenness. The blocks so prepared are known as 



Fig. 13a. Pavement of Round Blocks. 


«gapless” cedar blocks. Figs. 12 and 13 show the manner of con¬ 
structing wood pavements as practised in Europe. Fig. 13« shows 
a typical pavement of round blocks as laid in the Enited States. 

183. Number of Wood Blocks per Square Yard.— The number of 
rectangular blocks 9 inches long by 3 inches wide required per square 
yard is 44, and the area occupied by the joints will be equal to 108 

square inches. 



























110 


HIGHWAY CONSTRUCTION. 


The number of round blocks G inches in diameter required per 
square yard is 30, and the area occupied by interspaces will be 278.28 
square inches. 

184. The essentials necessary to the successful construction of 
wood pavements may be summed up as follows: 

(1) An unyielding and impervious foundation (concrete). 

(2) Sound and seasoned wood, either in its natural state or 
treated with a preserving compound. 

(3) An impervious filling for the joints between the blocks. 

185. Foundations. —As with all other paving materials so with 
wood, without an unyielding foundation it is impossible to preserve 
a smooth surface. The foundations most commonly employed in 
the United States are wanting in solidity; in the majority of cases 
the blocks are set in sand spread on the natural soil; in others they 
are set on one or two layers of plank laid on sand. The advantage 
claimed for the first method is cheapness ; the advantages claimed 
for the second method are, first, that the flooring of planks dis¬ 
tributes the weight or pressure applied to one block over a large 
surface, and, second, that the boards by their elastic action reduce 
the wear of the blocks. This latter claim is fallacious and incon¬ 
sistent with the method of construction, for the sand bed on which 
the planks are laid is supposed to solidly support them, if it does 
so the planks cannot yield elastically under pressure. 

186. The Chief Cause of Failure in pavements laid on a foundation 
of sand and planks is that, as soon as leakage, even to the slight¬ 
est extent, commences and the surface-water finds its way downward 
between the blocks, there is nothing to prevent its reaching and sat¬ 
urating the substratum of sand; since the boards, although close-laid, 
have not water-tight joints, the water will pass through them with 
comparative freedom. The saturated substratum becomes mobile 
and subject to movement under variations of pressure. Conse¬ 
quently when a load passes over the surface, the boards, opposing 
an inconsiderable resistance to deflection, are pressed downwards bv 
the load, and they recover their normal position when the load 
passes away. In this manner a pumping action is set up, and the 
sand and water, mixed with other loose matter at the bottom, is 
pumped up to the surface in the form of mud and slime. Thus 
the pavement becomes gradually undermined, and the undermining 
process is accelerated by the form of the pavement itself, which 



WOOD PAVEMENTS. 


Ill 


presents a continuous diaphragm under which the exhausting pro¬ 
cess is extended as by a diaphragm-pump. The wetter the weather 
the greater is the action of undermining. 

In addition to the general liability of leakage through the pave¬ 
ment, there is a special difficulty in keeping it water-tight at the 
curb, where it is comparatively overhung and unsupported, and 
where there is at the same time a constant supply of water for 
penetration so long as there is any water in the gutter. 

A serious consequence of the flexibility of the pavement is the 
numerous breakages of the blocks by splitting, caused by the un¬ 
equal strain and leverage of the load on blocks which are supported 
by a floor partly non-resisting and partly resisting. 

187, Quality of Wood.—The question as to which of the various 
kinds of wood available is the most durable and economical has not 
been satisfactorily determined. Many varieties have been tried. In 
England preference is given to Baltic fir, yellow pine, and Swedish 
yellow deal. In the United States the variety most used (on ac¬ 
count of its abundance and cheapness) is cedar; yellow pine, 
tamarack, and mesquite have also been used to a limited extent. 
Cypress and juniper are being largely used in some of the Southern 
States. 

Hard woods, such as oak, etc., do not make the best pavements; 
such woods become slippery. The softer, close-grained woods, such 
as cedar, cypress, and pine, wear better and give good foothold. 

The wood employed should be sound and seasoned, free from 
sap, shakes, and knots. Deflective blocks laid in the pavement 
will quickly cause holes in the surface, and the adjoining blocks 
will suffer under wear and the whole surface will become bumpy. 

188. Chemical Treatment of Wood.—The great enemy of all 
wood pavements is decay, induced by the action of the air and 
water. Wood is porous, absorbs moisture, and thus hastens its own 
destruction. Many processes have been invented to overcome this 
defect, such as: 

(1) Burnettizing .—This process consists in impregnating the 
wood with a solution of 1 pound of chloride of zinc to 4 gallons of 
water. Timber treated by simple immersion requires to remain in 
the solution for about two days for each inch in thickness, and 
after removal requires to be left to dry for about 14 to 20 days. 

The process is more expeditiously performed by forcing the 



112 


HIGHWAY CONSTRUCTION. 


solution into the pores of the wood with a pressure of 150 pounds 
to the square inch. 

The chief advantage of this process is that it renders the wood 
incombustible. 

(2) Kyanizing .—In this process the timber is immersed in a 
saturated solution of corrosive sublimate (bichloride of mercury) in 
a wooden tank, put together so that no metal of any kind can come 
in contact with the solution. 

One pound of corrosive sublimate to 10 gallons of water is used 
when a maximum strength is required, and 1 pound to 15 gallons 
of water when a minimum, according to the porosity of the timber ; 
with the latter proportion, 1J pounds will be sufficient for 50 cubic 
feet of timber. 

The time required to saturate the timber depends on its thick¬ 
ness. Twenty-four hours are usually allowed for each inch in thick¬ 
ness for boards and small timber; large timber requires from a 
fortnight to three weeks. 

(3) Creosoting .—This process consists in impregnating the 
wood with the oil of tar called creosote , from which the ammonia 
has been expelled, the effect being to coagulate the albumen and 
thereby prevent its decomposition, also to fill the pores of the wood 
with a bituminous substance that excludes both air and moisture, 
and which is noxious to the lower forms of animal and vegetable 
life. In adopting this process all moisture should be dried out of 
the pores of the timber. The softer woods, while warm from the 
drying-house, may be immersed at once in an open tank containing 
hot creosote oil, when they will absorb about 8 or 9 pounds per 
cubic foot. For hard woods, and woods which are required to 
absorb more than 8 or 9 pounds of creosote per cubic foot, the 
timber should be placed in an iron cylinder with closed ends, and 
the creosote, which should be heated to a temperature of about 
120° Fahr., forced in with a pressure of 170 pounds to the square 
inch. The heat must be kept up until the process is complete, to 
prevent the creosote from crystallizing in the pores of the wood. 
By this means the softer woods will easily absorb from 10 to 12 
pounds of the oil per cubic foot. 

The most effective method, however, is to exhaust the air from 
the cylinder after the timber is inserted, then to allow the oil to 
flow in, and when the cylinder is full to use a force-pump with a 




WOOD PAVEMENTS. 


113 


pressure of 150 to 200 pounds per square inch, until the wood has 
absorbed the requisite quantity of oil, as indicated by a gauge 
which should be fitted to the reservoir-tank. 

The oil is usually heated by coils of pipe placed in the reservoir, 
through which a current of steam is passed. 

The quantity of creosote oil recommended to be forced into the 
wood is from 8 to 12 pounds per cubic foot. 

Into oak and other hard woods it is difficult to force, even with 
the greatest pressure, more than 2 or 3 pounds of that oil. 

The advantages of this process are, the chemical constituents of 
the oil preserve the fibres of the wood by coagulating the albumen 
of the sap; the fatty matters act mechanically by filling the pores 
and thus exclude water; while the carbolic acid contained in the 
oil is a powerful disinfectant. 

The life of the wood is extended by any of the above processes 
by preserving it from decay, but such processes have little or no 
effect on the wear of the blocks under traffic. 

The process of dipping the blocks in coal-tar or creosote oil is 
injurious; besides affording a cover for the use of defective or sappy 
wood it hastens decay, especially of green wood; it closes up the 
exterior of the cells of the wood so that moisture cannot escape, 
thus causing fermentation to take place in the interior of the 
block, which quickly destroys the strength of the fibres and reduces 
them to punk. 

The best European practice of to-day favors untreated blocks. 

Considering the fact that in the United States large quantities 
of seasoned timber for paving cannot be obtained, it seems advisable 
that some artificial process of seasoning be employed. The most 
desirable process from an economic and sanitary point of view is 
the process of impregnation with oil of creosote. The success 
of this process depends upon the elimination of all moisture from 
the wood before the oil can be .injected. 

The woods which are best adapted to this treatment are those 
which are most absorbent and therefore the easiest and quickest 
destroyed, as the gums and cottonwoods. Cypress, cedar, pine, and 
porous oak are absorbent and can be successfully treated. 

The cost of creosoting is about from $12 to $18 per 1000 feet,, 
board measure. 

189. Dimensions of the Blocks.—As with the stone-block pave- 



114 


HIGHWAY CONSTRUCTION". 


ments so with, wood blocks, the gauge of a horse's hoof is the meas¬ 
ure of the maximum width. After numerous experiments with 
widths varying from 3 inches to 4^ inches, European engineers 
have decided upon the following dimensions: for rectangular 
blocks, width 3 inches, depth 6 inches, length 9 inches. 

The advantage of the narrower width is that, besides affording a 
more ready foothold when the pavement is slippery, narrow blocks 
have more stability than wide ones of the same depth. 

The length of a block should he suitably proportioned to the 
width; a length of 12 inches has been tried and found to be too 
much : the blocks were subject to splitting across. Nine inches 
appears to be the most suitable length. 

For round blocks the diameter should not exceed 6 inches; the 
depth may be the same as for the rectangular blocks, 6 inches. 
There is no advantage gained by a greater depth, for few wood 
pavements under the most favorable conditions retain a sufficiently 
good surface after about six years' wear without extensive repairs, 
and it is therefore not advantageous to lay blocks of a greater 
depth than will provide for a duration of seven years. Six inches 
is sufficient for this. 

190. Expansion of Blocks.—Wood blocks expand on exposure to 
moisture, and when laid end to end across the street the curbstones 
are liable to be displaced, or the courses of blocks will be bent into 
reverse curves. To avoid this the joints of the courses near the 
curb may be left open, or the courses next the curb may be left 
out until expansion has .ceased, the space being temporarily filled 
with sand. The rate of expansion is about 1 inch in 8 feet, but 
varies for different woods. The time required for the wood to 
become fully expanded varies from 12 to 18 months. By employ¬ 
ing blocks impregnated with the oil of creosote this trouble will be 
avoided. Blocks so treated do not contract or expand to any appre¬ 
ciable extent. 

191. Width of Joints.—Experience has demonstrated that the 
ide joints once thought necessary for foothold are not required. 

The best European practice of to-day is to make the joints as near 
one quarter of an inch as possible. Wide joints hasten the destruc¬ 
tion of the wood by permitting fibres to spread under the traffic. 

192. Filling for Joints.—The best materials tor filling the 
joints are bitumen for the lower two or three inches, and hy- 




WOOD PAVEMENTS. 


115 


draulic cement-grout for the remainder of the depth. The cement- 
grout protects the pitch from the action of the sun and does not 
wear down very much below the surface of the wood. 

193. Durability .—That wood pavements formed of well-seasoned 
wood properly laid on an unyielding foundation, with water-proof 
joints between the blocks, may last for many years without suffer¬ 
ing decomposition, has been amply demonstrated by the experience 
had with wood pavements in the city of London and other Euro¬ 
pean cities. 

From the following table and remarks it will he seen that the 
durability of wood pavements in London varies from 5 to 19 years, 
while in the LLiited States it varies from 3 to 7 years. 

Table XXXI shows the actual duration and cost of certain 
wood pavements in the city of London. 

TABLE XXXI. 

Duration and Cost of Wood Pavements in the City of London.* 


(Foundations are included, but no excavation.) 


Situation. 

Date when laid new. 

3 

First Cost per square 
yard. 

Total Cost of Repairs 
per sq. yd. during 
life. 

Average Cost per sq. 
yd. per annum. 

Cornbill. j 

( 

Gracecliurcli St.j 

Lombard Street. j 

Lothbury Street. -j 

Mincing Lane. j 

Bartholomew Lane.... | 

May 1855 
July 1865 
Nov. 1853 
June 1865 
May 1851 
Sept. 1860 
May 1854 
Sept. 1860 
July 1841 
Aug. 1860 
May 1854 
Aug. 1866 

yrs. ms. 
10 2 

6 8 

11 7 

6 0 

9 4 

10 7 

12 3 

6 1 

19 1 

13 0 

12 3 

5 • 5 

$2.92 

2.76 

3.04 

2.76 

2.28 

2.20 

3.00 

3.00 

3.44 

2.20 

3.00 

3.00 

$4.17 

2.35 

4.11 

1.66 

1.44 

4.90 

6.87 

0.83 

3.20 

5.47 

4.19 

0.95 

$0.70 

0.73 

0.61 

0.73 

0.39 

0.66 

0.80 

0.63 

0.35 

0.59 

0.59 

0.73 


* Report of Col. Haywood. 


“ The average life of the pavements in the three streets with the 
largest traffic was about 9 years, that of the three streets with the 
least traffic about Hi years. Nearly all before they were removed 

























11G 


HIGHWAY CONSTRUCTION. 


had been relaid over their entire surface, and some new wood intro¬ 
duced from time to time in lieu of that found too defective to 
relay.” 

“ It will be observed that the wood pavements last removed had 
a shorter life than the previous pavements. There is more than 
one reason for this, but it should be stated that nearly all would by 
relay and the introduction of some new wood have endured a few 

i 

years longer.” 

194. The wood pavements of Berlin have not proved as durable 
as those of London and Paris, and their use is practically aban¬ 
doned. Those of Frankfort (Ger.) laid under the Kerr system are 
giving satisfaction, and are said to be in as good condition to-day 
as when laid five years ago. The traffic on them is said to be con¬ 
stant and heavy. 

195. W. Weaver, Chief Engineer and Surveyor, Kensington,. 
London, says wood pavement of 5-inch creosote blocks will last ten 
years. 

196. In Chicago, Ill., in some streets wood pavements have 
lasted upward of ten years; in others they have become very rough 
and uneven in three or four years, while in the river-tunnels they 
have worn out in two years. 

197. The wood pavements of Washington, D. C., were of green 
hemlock, very badly constructed, and were destroyed by decay and 
dry-rot in about four years. 

198. In St. Louis, Mo., the average life of the Nicholson pave¬ 
ments was six years. Burnettized cottonwood used on Broadway 
developed decay in the third year. Mr. George Burnet, Street 
Commissioner of St. Louis, in his annual report for 1890 recom¬ 
mends the use of cedar-block pavement for medium-traffic streets. 

“ Since 1884 the practice has been to lay gum and cottonwood 
blocks impregnated with chloride of zinc on a foundation of 
cement concrete 6 inches thick, and the joints filled with hot bitu¬ 
minous composition. The channels are formed by iron studs 
driven in the side of the blocks to the head, which is half an inch.” 
(Thomas H. Macklind, District Engineer.) 

199. In Detroit, Mich., the Board of Public Works consider 
that cedar-block pavements will last eight years before extensive 
repairs are necessary, but that it is better to make repairs earlier. 

200. Mr. P. W. lioberts, City Surveyor of East Saginaw, Mich., 



WOOD PAVEMENTS. 


117 


in his report for 1889 says: “ Eight to ten years is the estimated 
life of cedar-block pavement laid on sand and board foundation. 
Allowing that our pavements will last ten years, then during the 
next ten years this city will have to do all its paving over again at 
a cost equal to about 85 per cent of the first cost. Would it not be 
better to change from cedar-block pavements to something more 
durable, though the first cost is greater ? On our business streets 
especially, the interruption of business by the tearing up and relay¬ 
ing of pavements is a thing to be considered in choosing our paving 
material.” 

201. According to the annual report for 1890 of the Board of 
Public Works of Duluth, Minn., 89,300 square yards of cedar-block 
pavement were laid in that year. The experience of the year shows 
that on grades between 4 and 13 per cent the best street surface is 
formed of blocks not more than 6 inches in diameter, laid in the 
usual manner, and with joints filled with grouting of Portland ce¬ 
ment and sand. It has been found necessary to keep the surface- 
water on top of the pavements on grades exceeding 7 per cent, and 
on this account a concrete foundation is regarded as indispensable. 

No tar composition was employed on the wood pavements in 
1890, as its use was found to hasten rather than retard decay in the 
climate of Duluth, making the extra cost of about 17 cents per 
square yard an unnecessary expenditure. On levels and light 
grades the dust from the gravel strewed over the surface at the 
time of completion of the pavement soon worked into the joints, 
making an impervious roadway. 

Owing to the fact that the subsoil of the streets in that city is a 
clay which causes the customary 3 inches of sand to be an insuffi¬ 
cient foundation, most of the pavement laid in 1891 was built on a 
Telford foundation. This consists essentially of two layers of 
stone. The first is 6 inches thick, composed of large stones 
thoroughly wedged together, all chinks being filled with smaller 
stones, and the whole surface covered with a layer of wet gravel 
compacted by a 20-ton steam-roller. The second layer is 2 inches 
thick, composed of broken stone not more than 2 inches in gieatest 
diameter, and covered with wet rolled gravel, like the first. On top 
of this foundation is sprinkled a thin layer of sand, which is 
covered by a course of 1-inch plank, affording a perfectly smooth 
and uniform surface on which to lay the blocks. 



118 


HIGHWAY CONSTRUCTION". 


Such a foundation has been found in Duluth to have the ad¬ 
vantage over concrete, which has heretofore been used on the 
best business streets, of having every portion of the sub-grade 
thoroughly compacted by the roller, the broken stone being forced 
down into the numerous soft spots. In preparing the subgrade for 
concrete foundations it was found that many spots had to be left 
unrolled, as they were too soft for the roller to pass over them. 
On the other hand, openings in Telford foundations for repairs to 
underground work cannot be as completely restored to their origi¬ 
nal condition as can concrete foundations, it being impracticable 
to thoroughly consolidate Telford macadam without the use of a 
heavy roller. 

202. Wear.—The wear of wood pavements is generally consid¬ 
ered to be as much due to the action of the horses* feet as to that of 
the wheels, and the action of the former is more destructive on 
steep grades; the wear is also increased by wide joints. 

The wear of wood pavements by the abrading action of traffic is. 
stated by various authorities as follows: 


TABLE XXXII. 

Wear of Wood Pavements. 


"Wear per annum under a traffic tonnage, 
per yard of width. 


Locality and Authority. 


1200 vehicles, per 12 hours.... 

1106 tons. 

1360 “ . 

279 “ . 

94,000“ . 

302,000 tons.. 


.81 inch 

£ “ 
.456 “ 
.065 “ 

i << 

.58 “ 


j King William Street, London. 

( Col. Haywood. 

j Parliament Street, London. 

I G. H. Stayton, Engineer, 
j Fleet Street, London. 

( G. H. Stayton, Engineer. 

\ Sloane Street, Loudon. 

} G. H. Stayton, Engineer. 

j Great Howard Street, Liverpool, 
( G. Dunscombe, Engineer. 


The wear in the latter years of the life of the wood was found 
to be greater than in the first years. The wear between street-car 
rails is about one third more than the remainder of the roadway. 

203. St. Paul, Minn.—The cedar-block pavement laid in 1882, 
on a plank and sand foundation, shows after seven years* use a wear 
of 2 to 2i inches under ordinary traffic; on recent investiga- 


















AVOOD PAVEMENTS. 


119 


tion the blocks shoAved very little decay, but the one-inch founda¬ 
tion-plank shoAved considerable. TA\ T o-incb planks are now used. 

204. St. Louis, Mo.—On Third Street, with a traffic of 2400 
vehicles in 24 hours, 6-inch blocks of prepared cottonAvood wore 
down 1^ inches in seven years. 

205. The cost of construction of wood pavements ranges be- 
tAveen $1.00 and $4.00, depending upon the quality of the Avood 
and Avhether it be plain or creosoted, and upon the character of the 
foundation. 

Table XXXIII shows the cost in various localities in the United 
States. 


TABLE XXXIII. 

Extent and Cost of Wood Pavements in Various Localities in the 

United States. 


Cities. 


Extent. Cost of Construction 

Miles. per square yard. 


Chicago, Ill. 

Detroit, Mich. 

St. Paul, Minn. 

Milwaukee, Wis. 

Minneapolis, Minn. 

Omaha, Neb. 

Springfield, Ill. 

Grand Rapids, Mich. 

Toledo, Ohio. 

Washington, D. C. 

St. Louis, Mo. 

Elmira, N. Y . 

St. Joseph, Mo.... 

East Saginaw, Mich. 

*Toronto, Can. 

^London, Eng. (City)... 
“ “ (Vestries) 

^Birmingham, Eng. 

*Paris, France. 


410.00 

116.19 

35.97 

30.00 

25.85 

25.00 

20.00 

14.63 

12.09 

0.60 

0.19 


16.59 


109.57 


6.00 

47.00 

6.00 


$1.15 

1.82 

$1.20 to $1.40 
1.05 “ 1.25 
0.95 “ 1 99 
1.80 
1.30 
1.00 
1.96 

3.56f 
3.06 
1.53 
1.40* 
1.10 § 

1.80 || 
2.65 f 
1.40 f 

$3.00 to $4.30 

2.52 
4.60 ** 


* Foreign cities for comparison. 

f Treated blocks. % Plank foundation. § Gravel foundation. 

| Cedar on concrete. If Tamarack on concrete. 

** Includes about 30 cents for the municipal tax on the material used. 
































120 


HIGHWAY CONSTRUCTION. 


206. Cost of Maintenance.—With regard to the cost of mainte¬ 
nance in the United States but little information can be obtained. 
St. Louis, Mo., reports the cost of maintaining pine-block pavement 
as 5 cents per square yard per annum, burnettized cottonwood at 
4-I to 6 cents. London, England, reports the cost of maintenance at 
from 16 to 36 cents per square yard per annum, or including all 
renewals 44 cents per annum. In Paris the cost ranges from 46 to 
54 cents. 

The practice of the companies engaged in the construction of 
wood pavements in Europe is to guarantee to keep the pavement in 
repair free of charge for one or two years, and then for so many 
years after at so much per annum. About $3.36 per square yard is 
generally the first cost of construction, and 24 cents the annual 
charge for maintenance. 

Table XXXIV shows the annual cost of maintaining certain 
wood pavements in London. 


TABLE XXXIV. 

First Cost and Tendered Cost per annum for Maintaining certain 
Wood Carriageway Pavements in the City of London. 


Situation. 

’ 

Date when laid. 

Name of Contractor. 

Years to be main¬ 
tained by con¬ 
tractor. 

First Cost per square 
yard. 

King William St. 

Feb. 1873 

1 Improved ) 

-< Wood. > 

16 

$4.32 

Ludgate Hill. 

Nov. 1873 

( Pav. Co. j 
Ditto 

16 

4.32 

Portions of Great) 





Tower St. and V 

Sept. 1873 

Ditto 

16 

3.84 

Seething Lane. ) 







f 1 yr. free, 15 yrs. ) 
1 at 36 cts.=$5.40 j 

j 1 yr. free, 15 yrs. | 
| at 36 cts.=$5.40 ) 

j 1 yr. free, 15 yrs. ) 
( at 30 cts.=$4.50 j 



207. Assuming the life to be 7 years, Mr. Stayton estimates 
the annual cost of wood paving in Chelsea, England, with a traffic 
of 500 to 750 tons per square yard of width per day, to be 42 cents 
per square yard, which includes the cost of original construction, 
repairing, renewals, and interest spread over 15 years. Cleansing 
























WOOD PAVEMENTS. 


121 


and sanding are estimated to cost 10 cents per square yard in ad¬ 
dition. 

208. Description of Various Systems of Wood Paving.—Cedar- 
block Pavement, Detroit, Mich.—The cedar-block pavements used 
here are made of sound blocks, stripped of bark, cylindrical in 
shape and not more than 9 inches nor less than 5 inches in diame¬ 
ter and 7 inches deep. These blocks rest on a bed of bank sand 
and gravel 6 inches deep, well compacted with a roller weighing 
2400 pounds. After the blocks are set they are rammed to a solid 
bearing with a rammer weighing 80 pounds; the spaces between 
them are filled with screened gravel rammed in with steel bars. 
The surface of the finished pavement is finally covered with gravel 
and sand to a depth of f of an inch. 

209. Mesquite-block Paving in San Antonio, Tex.—The blocks 
are hexagonal in shape, the minimum diameter being 4 inches and 
the maximum 8 inches, with a depth of 5 inches. The blocks are 
sawed with a slight batter, making the top about £ of an inch 
smaller than the bottom. 

The roadbed is excavated to the required depth and rolled 
with a steam-roller. 

The foundation is 6 inches of cement concrete. A cushion- 
coat of sand 1 inch in depth is spread over the concrete and the 
blocks bedded thereon. The joints are sand-filled. The cost per 
square yard, including foundation, is about $2.80. 

210. Asphalt Wood Pavement.—This is one of the more recently 
adopted pavements in England. It consists of a concrete founda¬ 
tion, on which is placed a coating of asphalt mastic one-half inch 
thick; the blocks are creosoted and are placed on the asphalt with 
spaces of half an inch between rows, and the joints are broken by a 
lap of at least two inches. The lower portion of the spaces for 2 to 
2i inches up is filled with-melted asphalt and the remainder with 
cement-grout and gravel. In London this costs $4.00 per square 
yard. 

211. Henson Pavement.—The Henson system, which has been 
largely used in London, is as follows: The blocks are bedded and 
jointed with ordinary roofing-felt, a strip of which, cut to a width 
equal to the depth of the blocks, is placed between every two courses. 
The joint is made as close as possible by driving up the blocks, as 
every eight or ten courses are laid, with heavy mallets, a plank being 






122 


HIGHWAY CONSTRUCTION. 


laid along the face of the work; a perfectly close and slightly elastic 
joint is thus formed. A continuous layer of felt is likewise laid 
over the concrete foundation to give a slightly elastic bed to the 
blocks. The surface of the pavement is dressed over with a hot 
bituminous compound, and covered with fine clean grit. The 
blocks are laid in courses at right angles to the curb, any change in 
the latter being accommodated by shorter courses ending with 
wedge-shaped blocks. At street-intersections the courses are laid 
diagonally or meeting at right angles. Two or three courses are 
laid parallel with the curb to form the gutter. 

212. Improved Wood-pavement Company.—The method em¬ 
ployed by this company in constructing the wood pavements in 
Paris is as follows : 

(1) Foundation .—This consists of a bed of Portland-cement 
beton 0.15 m. (6 inches) thick, with a top coat of cement mortar 
about 0.01 m. (f inch) thick. The beton is thus proportioned: A 
mixture of about one third sand and two thirds gravel is put in a 
bottomless box containing half a cubic meter (0.65 cubic yard), and 
after the removal of the box 100 kilograms (220 pounds) of cement 
are emptied on the heap. This is in the proportion, by volume, of 
about one seventh as much cement as there is sand and gravel, since 
1400 kilos is the mean weight of a cubic meter of good Portland 
cement heaped loosely. 

The sand was dredged from the bed of the Seine, and the gravel 
taken from pits on the seashore. The cement was furnished by 
the manufactory of Demarle & Lonquety, of Boulogne-sur-Mer. 

The paving-blocks have a uniform thickness and are not laid 
on the bed of beton until after it has set, in order to exactly 
preserve the curvature of the surface of the beton required for the 
convexity of the roadway. In the Avenue des Champs Elysees the 
convexity was 0.42 m. (lGl inches) in a width of 27 m. (87 feet 7 
inches), which represents a mean transverse slope of a little more 
than 3 in 100. This convexity, though less than first proposed by 
the company, appears to be a little excessive, and it seems that for 
roads under satisfactory drainage conditions the convexity might be 
diminished: 0.42m. is only a mean convexity, for, on account of 
the small longitudinal slope of the avenue, the grade of the gutters 
is not parallel to the grade of the street, but presents a series of 
short slopes from the hydrants to the sewer-openings; consequently 




WOOD PAVEMENTS. 


123 


the convexity varies from 0.39 m. (15J inches) at the hydrants to 
0.45 m. (17f inches) at the sewers. 

To exactly regulate the surface of the beton a series of trans¬ 
verse profiles were defined by stakes levelled to the grade of the top 
of the bed. Along each profile a strip of stiff beton was laid. The 
top of this beton was carefully levelled and smoothed and received 
a guide-rule, laid flat, whose thickness exactly corresponded with 
that of the beton coating. This series of rules thus formed a set 
of guides close together, between which it was easy with large 
straight-edges to level the beton to the required surface. The first 
levelling could never be more than approximate, the surface of the 
beton naturally remaining somewhat rough. The exact level re¬ 
quired, as fixed by the tops of the rules, was secured by the top 
coat of cement mortar which filled the spaces between the pebbles 
and made an exact surface. This mortar was first composed of 200 
kilos of cement to a cubic meter of sand (336 pounds to the cubic 
yard), but this proportion proving too small it was increased to 300 
kilos. It was always mixed with a great excess of water, so as to 
penetrate the interstices of the gravel. 

(2) Paving .—The covering is formed of small uniform blocks 
of red Northern fir, 0.15 m. (6 inches) high, 0.22 m. (8| inches) 
long, and 0.08 m. (3| inches) w r ide. These are set close lengthwise, 
with joints, transverse to the street, of about 1 centimeter (§ inch). 
The blocks are sent, ready for use, from England, where they were 
cut from planks of the ordinary size, 0.08 m. thick by 0.22 m. wide. 
The third dimension, taken in the length of the plank, forms the 
height of the block, bo that in position the fibres of the wood are 
placed upright. The blocks are superficially creosoted after being 
cut. 

When the foundation has set, two or three days after being laid, 
the blocks are set by the pavers. Owing to the light weight of the 
blocks the work of paving is very rapid. Between crossings the 
blocks are set in rows perpendicular to the axis of the street, with 
their longitudinal joints staggered exactly half the length of a 
block. The methods used at crossings to avoid a continuous joint 
parallel to the traffic are analogous to those used in stone-paving. 
Special precautions are taken to insure exact spacing and regu¬ 
larity of the rows. Before commencing a new row, a strip of wood 
whose thickness is exactly that of the required joint is set edgewise 





124 


HIGHWAY CONSTRUCTION. 


in contact with the last row, and the paver has only to set the ad¬ 
jacent blocks in contact with it. 

The blocks do not at first adhere to the foundation and are 
easily displaced after the removal of the strips; to maintain 
them in place, as soon as the strips are taken out a small quantity 
of bitumen is poured into the joints. This liquid material fills the 
small spaces that may exist under the blocks and partially fills the 
joints, and in solidifying effectually seals the blocks. 

The joints are then filled by a thin grouting of neat Portland 
cement, distributed by the aid of a broom. This is done at least 
twice to insure perfect filling and the essential impermeability. 

The pavement cannot be opened for traffic until after the ce¬ 
ment in the joints has completely set, for which a delay of four or 
five days is considered necessary. During this interval the last 
operation is performed, viz., spreading a thin layer of dry sharp 
sand over the surface. The company claims that this dressing, 
crushed under the action of the wheels, incrusts itself in the wood 
and lends resistance to the wearing surface. It seems more prob¬ 
able that this coating is simply to protect the fresh mortar from 
the direct action of the wheels, for it can be maintained but a very 
short time on a travelled road, and is soon transformed into a dis¬ 
agreeable greasy mud. 

212a. Creosoted pine blocks have been extensively laid in Gal¬ 
veston, Tex., and seem to be in much favor there. The blocks are 
cut from yellow pine and are 5 inches thick, 5 inches deep, and 
10 inches long; they are impregnated by the vacuum process with 
twelve pounds of creosote per cubic foot. 

The method of forming the pavement is as follows: The sandy 
soil of the streets is compacted by saturating it with water, then 
shaped to the required contour, and the blocks laid directly upon 
it; the joints are filled with sand and the blocks are rammed, after 
which the surface is flooded with coal-tar sufficiently liquid to pene¬ 
trate the joints; a coating is then applied composed of asphaltic 
paving-cement or asphaltum and dead oil, after which the surface 
is covered with a thin layer of clean sharp sand. 

213. Heads of Specifications for Wood-block Pavement. 

(1) Preparation of Roadbed. 

(2) Foundation. 

(3) Cushion-coat— The cusliion-coat shall consist of a layer of 



WOOD PAVEMENTS. 


125 


dry, clean, sharp sand evenly spread on the concrete to a depth of 
one-half inch. 

Note.— Asphaltlic paving-cement may also be used for the 
cushion-coat; or the blocks may be laid directly upon the concrete. 

(4) Quality of the Blochs. —The blocks shall be of 
timber, sound and thoroughly well seasoned, free from all sap, 
shakes, large and loose knots or other defects. 

Note. —If the blocks are to be creosoted, the number of pounds 
of creosote that should be absorbed in a cubic foot of the wood 
should be specified; this is generally about 10 lbs. of creosote to 1 
cubic foot of wood. 

(5) Size of the Blochs. —(Rectangular:) The blocks must not be 
less than 6 inches nor more than 12 inches in length by 3 inches in 
width and 6 inches in depth. (Round Blocks:) The blocks shall 
not be less than 4 inches nor more than 8 inches in diameter, 
with a uniform length of 6 inches. Each block to be of uniform 
cross-section from end to end, the ends to be sawn off at right 
angles to the axis. The diameter of the block preferred is 4 inches, 
and 70 per cent of the whole number of blocks furnished must be 
of this size. 

(6) Inspection and Culling. —The blocks will be inspected after 
they are brought on the line of the work, and all blocks which in 
quality and dimensions do not conform strictly to these specifica¬ 
tions will be rejected and must be immediately removed from the 
line of the work. The contractor must furnish such laborers as 
may be necessary to aid the inspector in the examination and culling 
of the blocks ; and in case the contractor neglect or refuse to fur¬ 
nish said laborers, such laborers as in the opinion of the 

may be necessary will be employed by said , and the 

expense thus incurred by will be deducted and paid 

out of any money then due or which may thereafter become due to 
said contractor under the contract to which these specifications 
refer. 

(7) Cushion-coat. — On the concrete foundation a layer of clean 
sharp sand, free from moisture, will be evenly spread to a depth of 
one-half inch. The sand, if not dry, must be made so by the appli¬ 
cation of artificial heat in such apparatus as may be suitable for 
the purpose and approved of by the engineer. 

(8) Laying the Blochs. —The blocks (rectangular) shall be set 



126 


HIGHWAY CONSTRUCTION. 


on the cusliion-coat with the fibre vertical, in parallel courses, with 
the length of the blocks at right angles to the axis of the street; 
any change in the direction of the latter being accommodated by 
shorter courses ending in wedge-shaped blocks. No joints shall 
exceed f of an inch in width. The blocks shall be so laid that all 
longitudinal joints will be broken by a lap of at least 2 inches. At 
street-intersections the courses are to be laid diagonally as shown 
in Fig. 13. 

The gutters will be formed by three courses of blocks laid par¬ 
allel to the curb; the course adjoining the curb will be left out 
until expansion has ceased. The space so left unpaved will be filled 
with sand. 

(9) Laying the Blochs (round blocks).—The blocks will be laid 
on the cushion-coat, in parallel rows across the street and in close 
contact with each other. Split blocks shall be used adjoining the 
curbs, around sewer-manhole heads, and at such other places as the 
engineer may direct but no split blocks shall be laid in the main 
pavement. 

(10) Ramming .—After the blocks are so laid they shall be 
rammed to a solid bearing with a hand rammer weighing not less 
than 50 pounds. All blocks which sink below the general level 
shall be taken out and sufficient sand poured in to bring them to 
the required level. 

(11) Jointing (rectangular blocks).—The joints shall be care¬ 
fully filled with a grout composed of two parts of fine, sharp, clean 
sand and one part of Portland cement of an approved brand. 

(12) Jointing (round blocks).—The interstices between the 
blocks shall be filled for a depth of 2 inches from the bottom with 
clean, screened gravel, the pebbles of which shall not be less than 
£ inch nor more than ^ inch in diameter, then hot paving-cement 
shall be poured in to a depth of 2 inches and sufficient gravel 
poured in to fill the joints flush with the top of the pavement, then 
more paving cement poured in until the joints are full and will 
absorb no more. After which a layer half an inch deep of dry, 
sharp sand will be spread uniformly over the surface of the pave¬ 
ment. 

The quantity of paving-cement required per square yard will 
not be less than 3^- gallons. This quantity must be brought upon 
the ground, and whatever may remain after the completion of the 





WOOD PAVEMENTS. 


07 

-rJ I 


work will be the property of the city. Any wastage of paving- 
cement by pouring over the surface instead of between the blocks 
must be covered with a sufficient quantity of fine dry gravel to 
absorb it. The amount so wasted will be estimated, and the quan¬ 
tity so estimated must be replaced by the contractor at his own 
expense. 

(13) Composition of Paving-cement. —The paving-cement will 
be composed of the residuum obtained from the direct distillation 
of coal-tar and creosote oil, in the proportion of 50 gallons of oil to 
1 ton of residuum. The two ingredients will be melted together in 
suitable iron boilers having a capacity of not less than 1 ton. 
The cement shall be poured into the joints when in a boiling state. 

(14) Quality of the Gravel. —The gravel used for filling the 
joints shall be free from sand, clay, or other objectionable sub¬ 
stances. 

(15) Interpretation of specifications. 

(16) Omissions in specifications. 

(17) Engineer defined. 

(18) Contractor defined. 

(19) Notice to contractors, how served. 

(20) Preservation of engineer's marks, etc. 

(21) Dismissal of incompetent persons. 

(22) Quality of materials. 

(23) Samples. 

(24) Inspectors. 

(25) Defective work. 

(26) Measurements. 

(27) Partial payments. 

(28) Commencement of work. 

(29) Time of completion. 

(30) Forfeiture of contract. 

(31) Damages for non-completion. 

(32) Evidence of the payment of claims. 

(33) Protection of persons and property. 

(34) Indemnification for patent claims. 

(35) Indemnity bond. 

(36) Bond for faithful performance of work. 

(37) Power to suspend work. 

(38) Right to construct sewers, etc. 



128 


HIGHWAY CONSTRUCT 10X. 


(39) Loss and damage. 

(40) Old materials, disposal of. 

(41) Cleaning up. 

(42) Personal attention of contractor. 

(43) Payment of workmen. 

(44) Prices. 

(45) Security retained for repairs. 

(46) Payment, when made. Final acceptance. 

214. Maintenance of Wood Pavements by Contract.—The con¬ 
tractor will undertake the maintenance of the pavement for 
years (usually eighteen) from day of 189 . This 

maintenance will consist in preserving the surface and regularity 
of the profile, and in making all general or partial repairs neces¬ 
sary to keep the roadway in a perfect state, even if the dilapida¬ 
tions are the result of accidental causes, as fires, sinking of the 
subsoil, etc., excepting only defects caused by the digging of 
trenches. 

The contractor will be required to make general repairs on al 
portions of the road where there is: (1) A reduction of the curve 
diminishing the original pitch by at least one fourth. (2) Where 
the thickness of the paving-blocks has been worn away f of an inch 
or more. (3) Depressions or partial defects of the road numerous- 
enough to make it rough, the engineer being judge of the time 
when it shall be required for this reason. 

The concrete foundation will generally be preserved by simply 
adding Portland-cement mortar on top if there is room for it; the 
removal of the foundation is not obligatory except in case of its bad 
condition. 

Besides the general repairs the contractor must insure the con¬ 
stant good state of the pavement by partial repairs that may be 
necessary. He must immediately replace paving-blocks that are 
decayed, crushed, broken, or depressed by any cause whatever, also 
those which have become impregnated with urine or other offen¬ 
sive liquids and emit a bad odor. 

He must repair holes whose depth reaches | of an inch for a 
length of 3 feet in any direction. 

At the junction-lines of the wooden pavement with the stone or 
asphalt pavement, paving-blocks will be replaced when they shall 
have been worn away T 7 g- of an inch. 




WOOD PAVEMENTS. 


129 


In all partial repairs the new pavement must have the same 
level as the adjacent pavement; no projections will ne permitted. 
If any of the defects enumerated in this article are not repaired 
within three days after notification, a charge of dollars per 

day will be deducted from the contract price for each day’s delay. 

Renewals of the pavement over trenches opened for any cause 
must be executed in the 'same time and under the same restrictiors 
as above. The renewed portions will immediately pass into ti e 
maintenance of the contractor, who must preserve them in accord¬ 
ance with the foregoing conditions. No claims will be allowed for 
repairs required by sinking of the earth. The contractor will only 
be paid for the area of the trenches measured when filled up. 

The old material and rubbish from repairs must be entirely 
removed from the street on completion of the work, in default of 
which the contractor will be subjected to a penalty of 
dollars per day for each deposit not removed. 

At the expiration of the maintenance period the pavement 
must be delivered in perfect condition. Three months before the 
expiration of the contract term the engineer will make a statement 
showing the condition of the pavement. The pavement shall not 
be received unless it satisfies the following requirements: (1) 
There must be no holes having a depth of f of an inch in any 
square yard of the pavement. (2) The transverse contour of the 
surface must not at any point be reduced so that the rise is less, 
than four fifths of its original value. (3) The thickness of the 
blocks must at no place be less than 2 inches. After the engin¬ 
eer’s inspection and report the contractor will be allowed three 
months to place the work in the required condition. 

The contract price fixed for the renewal of the pavement will 
be paid for the repairs over trenches, the demolition of the pave¬ 
ment being at the expense of the person or companies opening the 
trench. The contractor must, if necessary, relay the pavement 
with entirely new materials, and can make no claim for damages to 
the work or its maintenance. 

The price to be paid for maintaining the pavement in the above- 
described condition is cents per square yard, and will be 

payable quarterly during the contract period. Ten percentum of 
the amount payable quarterly will be retained and shall not be due 
or payable until the expiration of the contract period. 





130 


HIGHWAY CONSTRUCTION. 


The price to be paid per square yard for the renewal of the 
pavement over trenches is dollars. 

215. Specifications for Laying Cedar Pavement in Chicago.— 

Before paving the street shall be graded to conform to stakes or 
profiles to be given by the engineer in charge, and thoroughly 
flooded, rammed, and rolled to give it a solid bed. 

Pawing. —1st. The pavement shall not be laid on any street 
until the material thereof shall have been made firm and unyield¬ 
ing, and the contractor shall assume all the responsibility therefor. 

2d. A bed of clean lake-shore sand, not less than three (3) inches 
in depth, shall be smoothly and evenly spread over the surface of 
the street, and compactly rammed and rolled down. 

3d. A foundation of two- (2-) inch sound common hemlock 
plank, to be laid lengthwise of the street, close together upon one- 
(1-) inch by eight- (8-) inch pine stringers under the ends and 
centres. Stringers to be firmly bedded in the sand. 

4th. Upon said foundation live cedar blocks, free from bark and 
perfectly sound, not less than four (4) inches nor more than eight 
(8) inches in diameter, and six (6) inches in length, shall be placed 
on end, close-laid, resting properly on their bases and well driven 
together. All blocks more than eight (8) inches in diameter shall 
be split and the corners cut sufficiently to make good joints with 
adjacent blocks. 

No split blocks of less than three (3) inches in thickness will be 
allowed. 

All knots or excrescences must be cut otf to make the blocks 
practically uniform in diameter throughout their length. 

No interstice between the blocks to be more than one and one- 
half (1|) inches nor less than three quarters (f) of an inch. 

No square holes will be allowed, nor must two split sides come 
together. 

The surface of the pavement must be true and uniform. 

In case any loose or defective blocks shall be found in the pave¬ 
ment, they shall be removed and replaced by perfect blocks of 
proper size, and so much of the pavement as may be necessary to 
make the work perfect shall be taken up and relaid at the expense 
of the contractor. 

The blocks will be carefully inspected after they are brought on 
the line of the work, and all blocks or other material which, in 






WOOD PAVEMENTS. 


1 31 

quality or dimensions, do not strictly conform with these specifica¬ 
tions, or which may be otherwise defective, shall be rejected, and 
must be immediately removed from the line of the work by the 
contractor. The contractor will be required to furnish such labor¬ 
ers as may be necessary to aid the inspector in the examination and 
culling of the blocks and other material; and in case the contractor 
shall neglect or refuse so to do, such laborers as in the opinion of 
the Commissioner of Public Works may be necessary will be em¬ 
ployed, and the expense incurred shall be deducted from any money 
then due or which thereafter may become due the contractor. 

5tli. The spaces between the blocks to be filled with clean, dry 
lake-shore gravel, of one fourth (£) to one (1) inch in size, the pro¬ 
portion of said gravel to be such as to completely fill the interstices, 
and shall be thoroughly rammed with proper tools and by compe¬ 
tent and experienced help, and again filled with the same kind of 
gravel and again thoroughly rammed. 

In the above-described ramming the filling in each interstice 
must be struck three full blows and driven down well. Two com¬ 
petent rammers must be constantly employed after each paver. 
No teams will be allowed on the pavement before it is properly 
rammed. After ramming the pavement will be flooded with hot 
composition, not less than one and one half (1|) gallons per square 
yard being used. The tar will be distributed with a three- (3-) 
gallon kettle, the work to be done in sections as the Commissioner 
of Public Works, or his representative, may direct. 

6th. After which clean, dry lake-shore gravel, about one fourth 
(^) inch in size, shall be spread over the street in such quantity that 
when swept all the interstices between the blocks will be thoroughly 
filled. When the gravel is put on the second and third time there 
must be enough space left between the portions rammed once and 
twice for the other portions to enable the inspector tb see that 
every part of the street is thoroughly rammed. 

7th. The whole surface will be swept over and covered with hot 
composition not less than one half (^) gallon per square yard, and 
immediately covered with dry roofing-gravel, or gravel screened 
from that used to fill the spaces between the blocks, said covering 
to be not less than one (1) inch thick. All gravel used here must 
be lake-shore gravel, entirely free from sand or pebbles, over one 
half (i) inch in size, and dried and heated enough to prevent the 
chilling of the composition. The gravelling and tarring must be 




132 


HIGHWAY construction. 


completed each day to within fifteen (15) feet of the end of the 
paving, and the top dressing to within fifty (50) feet. If the gravel 
and pavement becomes wet before the tarring is completed, the same 
may be ordered taken by the Commissioner of Public 1\ orks. 

The composition used will be furnished by the city in the ordi¬ 
nary portable tanks at some point within the city limits; the same 
to be transferred by the contractor from the receiving point to the 
work, and the empty tanks returned to the place of reception; the 
contractor to furnish the necessary fuel and labor to keep the com¬ 
position at a temperature of not less than 300 degrees Fahrenheit, 
and be at all times responsible for the tanks and their contents 
while in his care. The Department reserves the right to increase 
or diminish the quantity of the composition used, 

216. Extracts from the Specifications for Laying Cedar-block 
Pavements in Minneapolis. — Street Railway .—Upon such streets as 
the street-railway company has tracks, it shall be the duty of the 
street-railway company to lower its tracks to the grade of the pave¬ 
ment to be laid. The said street-railway company in lowering its 
tracks shall deposit the material excavated on the outside of its 
tracks, and the contractor will be required to remove the same at 
the same price per cubic yard as for extra excavation. It is, how¬ 
ever, expressly understood that when the street-railway company 
has double tracks the contractor will be required to excavate and 
pave the spaces between said double tracks in the same manner as 
the remainder of the roadway, and shall receive the same price per 
square yard for said paving as he shall receive per square yard for 
the remainder of the paving of said roadway. 

Blocks .—The blocks must be of the best quality of cedar, live 
and perfectly sound, and when in place be free from projecting 
knots and bark. They must be of a uniform length of six (6) 
inches, and have a diameter of not less than four (4) inches nor 
more than (10) ten inches. No blocks exceeding ten (10) inches in 
diameter will be allowed in the work either whole or split, ami 
it is hereby expressly understood that the contractor will not U 
allowed to deposit upon the line of the work any blocks having the 
diameter greater than ten (10) inches, or any blocks turned from 
a post of a greater diameter than ten (10) inches. 

It is expressly understood that the contractor will be required 
to repair in a satisfactory manner any paving that may settle or 





WOOD PAY EM ENTS. 


133 


become defective on account of improper workmanship or material, 
or on account of the laying or construction of water-mains,-sewers, 
gas-pipes, or making sewer, water, or gas connections, or conduit- 
laying, or any excavations allowed to be made in the street by the 
city council, which may have been done previous to the laying of 
said pavements, without cost to the city of Minneapolis. 

Flooring .—Upon the finished sub-grade must be laid a floor of 
sound white-pine plank, of the quality equal to the grade known 
as first common lumber, as the city engineer and the city council 
may determine. These plank must be laid lengthwise of the 
street with close joints, and be two (2) inches thick, from eight (8) to 
twelve (12) inches wide, and from fourteen (14) to sixteen (16) feet 
long. They must have a bearing at each end and in the centre upon 
a one- (1-) inch by eight- (8-) inch stringer firmly bedded in the 
sand. Planks not less than six (6) inches wide may, however, 
be used in order to form the crown of crossings. 

Laying .—The blocks must be placed upon their ends in close 
contact with each other, on a clean floor. The joints between the 
blocks must not exceed two inches in their longest direction. 
Blocks of less diameter than six inches must not be split, nor must 
a piece of less size than half the block be used. The corners of 
split blocks must be trimmed so as to make proper joints. Un¬ 
necessary splitting of blocks will not be allowed. 

Joints to be Filled .—The joints or spaces between the blocks 
must be filled in the following manner: First, fill the joints by 
sweeping clean, screened gravel, the pebbles of which shall be of a 
size not exceeding one inch in their largest diameter, into them. 
After sweeping, the surface of the pavement must be clean and free 
from gravel, then the gravel must be thoroughly tamped. This 
process must be repeated a second time. Gravel of the same kind 
as before used must be spread over the surface to a depth of not 
less than one inch above the top of the blocks. 

Gutters and Corners of Crossings must be made as follows: The 
outside plank shall be 3 inches thick, 16 inches high, and 20 feet 
long on 80-foot streets, and 3 inches by 16 inches by 16 feet on 60- 
foot streets, and held in place by not less than six posts of 3 by 6 by 
30 inches, driven to a depth of three inches below the top and 
equidistant along the length of the plank. There shall be a plank 
2 inches thick, 10 feet long, for 80-foot streets, and 2 inches by 8 






134 


HIGHWAY CONSTRUCTION. 


feet on 60-foot streets, and of a width of 3 inches less than the 
depth of the gutter, placed against the curb to support the gutter- 
cover, which shall be made of two pieces of 3 by 12 inches by 10 
feet on 80-foot streets, and of 3 bv 12 inches by 8 feet on 60-foot 
streets, fastened together with four pieces, 2 by 19 inches, well 
nailed with six 30d. spikes to each piece. The top of the outside 
gutter-plank on the slope of the crossing shall be trimmed to con¬ 
form to the top of the paving. In making proposals the contractor 
will state a price which shall include cost of excavating eight (8) 
inches below the top of the finished paving; also the furnishing 
and putting in place complete of all lumber required in the gutter 
crossings and covers. The contractor will state a price per cubic. 
Yard for extra excavation. 





CHAPTER V. 


ASPHALTUM AND COAL-TAR PAVEMENTS. 

217. Asphalt was first employed for street-paving in Paris in 
1838, but it was not employed to any great extent until 1854. In 
1869 it was introduced into London, and since then has been ex¬ 
tensively used throughout Europe. 

The success which attended this pavement led to its introduc¬ 
tion into America. The great cost of importing the materials from 
Europe made the pavement so expensive as to induce American 
inventors to seek to manufacture a material which should have 
similar qualities. The result was the introduction of many sub¬ 
stitutes and imitations, the majority of which proved defective. 

The great cost of the imported material and the failure of the 
substitutes directed attention to the deposits of natural bitumen on 
the island of Trinidad, which could be brought here very cheaply. 
Experiments were made which demonstrated the possibility of mak¬ 
ing a mastic with Trinidad bitumen as its cementing material, as 
strong, elastic, and durable as that imported from Europe; but it 
was only after some years that this process was introduced and made 
a commercial success. 

218. The difference between the asphalt pavements of Europe 
and those of America is due to the character of the materials. The 
former are composed of limestone rock naturally impregnated with 
bitumen, while the latter are composed of an artificial mixture cf 
bitumen, limestone, and sand. The limestone in the European 
pavements becomes hard, smooth, and slippery under traffic, and 
is thus objectionable for general use in frosty latitudes. The 
granular nature of the sand used in preparing the Trinidad asplial- 
tum diminishes the tendency to wear smooth and materially lessens 
the slipping of horses. 

219. Although many deposits of bituminous rock are found in 

the United States, they have been used only to a limited extent, 

135 


136 


HIGHV. VY CONSTRUCTION". 


and the island of Trinidad continues to be the main source of supply 
for the United States. This is due entirely to its advantage in cost 
of transportation. The railroad freight rates from the place of the 
deposits practically shut out the bituminous rock of California and 
Kentucky from competition in the Eastern States, and a similar 
condition may be said to affect the sale of Trinidad asphaltum in 
the cities of Europe, since the bituminous limestones of Val de 
Travers and Seyssel, having the advantage in freights, control the 
markets. 

220. The cost of preparing the different varieties of asphaltum 
for street pavement is nearly the same; and as all appear to be about 
equally durable, the exclusive use of any one of them is due merely 
to the advantage in freights. 

4 

TYPE-SECTIONS OF ASPHALT PAVEMENTS. 



ASPHALT 2" 
BINDER /£” 

CONCRETE 5" 


Fig, 14. HEAVY-TRAFFIC PAVEMENT. 







































ASPHALTUM ANT) COAL-TAR PAVEMENTS. 


13 ? 



Fig. 15a. ASPHALT ON STONE BLOCKS. 


ASPHALT 2; 
BINDER l/z 

MACADAM 


Fig. 15b. ASPHALT ON MACADAM. 

221. The Advantages of Asphalt may be summed up as follows: 

(1) Ease of traction. 

(2) It is comparatively noiseless under traffic. 

(3) It is impervious. 

(4) It is easily cleansed. 

(5) It produces neither mud nor dust. 

(6) It is pleasing to the eye. 

(7) It suits all classes of traffic. 

(8) There is neither vibration nor concussion in travelling over it. 

(9) It is expeditiously laid, thereby causing little inconvenience 
to traffic. 

(10) Openings to gain access to underground pipes are easily 
made. 

(11) It is durable. 

(12) It is easily rapaired. 

222. Defects of Asphalt Pavement. 

(i) it is slippery under certain conditions of the atmosphere. 






























138 


HIGHWAY CONSTRUCTION. 


The American asphalts are much less so than the European on 
account of their granular texture, derived from the sand. The 
difference is very noticeable: the European are as smooth as glass, 
while the American resemble fine sand-paper. 

(2) It will not stand constant moisture, and will disintegrate if 
excessively sprinkled. 

(3) Under extreme heat it is liable to become so soft that it 
will roll or creep under traffic and present a wavy surface, and 
under extreme cold there is a danger that the surface will crack 
and become friable. (In Washington, D. 0., with a range of tem¬ 
perature from 5 to 150 degrees Eahr., no serious trouble has been 
experienced with the Trinidad asphalts.) 

(4) It is not adapted to grades steeper than 2-J percent. In 
the city of New York there are streets paved with asphalt on 
which the grade varies from 2 to 6 per cent, and Mr. North, 
C.E., states that the traffic has deserted Ninety-third Street, which 
is paved with granite on a grade of 5.15 per cent, for Ninety-fourth 
Street, which is paved with asphalt on a 6 per cent grade. (See 
also Art. 261.) 

(5) Repairs must be quickly made, for the material has little 
coherence, and if, from irregular settlement of the foundation or 
local violence, a break occurs, the passing wheels rapidly shear off 
the sides of the hole, and it soon assumes formidable dimensions. 
In London this is prevented by constant watchfulness. Workmen 
are employed to traverse the street with a light repairing outfit, 
and whenever a defect is observed it is patched at once, and so 
effectually that the spot cannot be distinguished. 

223. The strewing of sand upon asphalt renders it less slippery ; 
but in addition to the interference of the traffic whilst this is being 
done, there are further objections, viz., the possible injury by the 

{ sand cutting into the asphalt, the expense of labor and materials, 

' and the mud caused thereby which has afterwards to be removed. 

224. Although pure asphaltum is absolutely impervious and 
f insoluble in either fresh or salt water, yet asphalt pavements in the 

continued presence of water are quickly disintegrated. Ordinary 
rain or daily sprinkling does not injure them when they are allowed 
to become perfectly dry again. The damage is most apparent in 
the gutters and adjacent to overflowing drinking-fountains. This 
defect has long been recognized, and various measures have been 








ASPHALTUM AND COAL-TAIt PAVEMENTS. 


139 


taken to overcome it, or at least to reduce it to the minimum. In 
some cities ordinances have been passed seeking to regulate the 
sprinkling of the streets, and in many places the gutters are laid 
with stone, while in others the asphalt is laid to the curb and a 
space of 12 to 15 inches along the curb is covered with a thin coat¬ 
ing of asphalt cement. This latter mode is followed in Washington, 
D. C. It is said that the pavements formed of asphalt cement in 
which “ Maltha ” or liquid asphalt is used, instead of the residuum 
of petroleum, as the fluxing agent, are not affected by moisture. 

225. Asphalt laid adjoining centre-bearing street-car rails is 
quickly broken down and destroyed. This defect is not peculiar 
to asphalt. All other materials when placed in similar positions 
are quickly worn. Granite blocks laid along such tracks have been 
cut into at a rate of more than half an inch a year. The frequent 
entering and turning off of vehicles from car-tracks is one of the 
severest tests that can be applied to any paving material; more¬ 
over, the gauge of trucks and vehicles is frequently greater than 
that of the rails, so one wheel runs on the rail and the other 
outside. The number of wheels thus travelling in one line must 
quickly wear a rut in any material adjoining the centre-bearing 
rail. 

To obviate the destruction of asphalt in such situations it is 
usual to lay a strip of granite-block paving alongside of the rail. 
These blocks are laid alternately as headers and stretchers, so as to 
form a toothing into the asphalt. This pavement should be of 
sufficient width to support the wheels of the widest gauge using 
the street. 

226. Asphalt Pavement Injured by Illuminating-gas. —The 

asphalt pavements on some of the streets of Frankfort, Germany, 
became friable and porous. City Engineer Dehnhardt attributed 
this to the escape of illuminating-gas. This view was ridiculed by 
several German authorities on this material. The pavements were 
taken up, aud it was found that the gas-pipes had several leaks 
under the worst parts of the street. Some of the injured pavement 
and pieces of sound pavement were tested. The sound fragments 
were placed in a tube through which gas was allowed to flow. 
After a week the samples were reduced to the same friable condi¬ 
tion in which parts of the pavement had been found. The samples 
after several weeks' exposure to the atmosphere regained their 






140 


HIGHWAY CONSTRUCTION. 


original good condition. The explanation offered is that a portion 
of the carburetted hydrogen of the gas is absorbed by the asphalt, 
thus destroying its cohesion. 

227. Durability.—The systems adopted for the maintenance of 
asphalt pavements renders it difficult to ascertain their actual life 
under traffic. They are repaired immediately they need it, and as 
each repair is so much new material laid, the whole surface is 
really relaid in the course of years. Col. Haywood states that in 
his opinion asphalt will last without extensive repairs from four 
to six years, and that in the course of ten years the entire surface 
will have been renewed. 

228. That asphalt successfully sustains an enormous traffic is 
shown by the following figures: From London, Cheapside has a 
traffic of 13,772 vehicles in 24 hours; Mansion House Street, 
23,332 vehicles in 24 hours. Cornhill, Holborn Viaduct, and 
many others have a daily traffic of upwards of 12,000 vehicles. 
These streets are paved with asphalt. 

229. There are no streets in America or elsewhere in the world 
that have so much traffic as the above-mentioned London streets. 
Among the vehicles that travel on them are omnibuses loaded with 
passengers inside and out, light vehicles of all descriptions, carts, 
carriages, and brewery trucks loaded with tons of ale and porter. 

Cheapside was paved in 1870, and the pavement remained in 
constant use for 19 years, with of course extensive repairs; but up 
to 1889 the carriageway was never closed entirely for a general 
relaying of the pavement. In 1889, the contract for maintenance 
of the asphalt having expired, a new contract was made and a new 
surface of asphalt was laid. 

230. St. Louis, Mo.—“ The asphalt laid on Pine Street in 1883 is 
now in good condition after a test of eight years under a mixed traffic 
of 3000 vehicles in 12 hours from 7 a.m. to 7 p.m. The Avork was 
carefully executed, and consists of a G-inch hydraulic-cement 
concrete base, one-half inch cushion-coat and 2-inch surface or 
wearing coat, cross-section camber 0.50, width between curbs 36 
feet. Traffic is what may be termed building materials, residence 
supplies, and suburban. While it has been subjected to the heaviest 
loads hauled in the city with fair results, it must stand below 
granite for wear/’ (Report of Mr. T. H. Macklind, District En¬ 
gineer.) 






ASPHALTUM AND COAL-TAR PAVEMENTS. 


141 


231. Wear.—Asphalt is to a certain extent elastic and does not 
begin to wear until this elasticity is overcome by thorough com¬ 
pression. This is the case with no other paving material. Stone 
and wood begin wearing from the day traffic commences. Under 
ordinary traffic it may be estimated that it will take two years to 
complete the compression of asphalt, and the weight of a square 
foot of this pavement will at the expiration of that time be nearly 
the same as on the day it was laid, though the thickness is reduced 
during the first two years as much as it will be in the following- 
eight. The extent to which the thickness has been reduced is said 
to be as much as one fourth the original thickness. 

A pavement in Paris which had lost more than one fourth of 
its thickness was found to have lost only 5$ of its weight after 16 
years’ use. 

The pavement in Oheapside, London, after fourteen years’ use, 
shows a reduction, where not repaired, from its original thickness 
of 2^ to If inches. 

232. Cost of Construction. —The cost of construction varies 
with the locality, thickness of wearing surface, and kind of founda¬ 
tion. 

Table XXXV shows the extent and cost in several cities in 
America. 

In London the first cost is from $3.75 to $4.50 per square yard, 
including maintenance. The total annual expense varies from 33 
to 57 cents per square yard. 

In Omaha, Neb., the first cost per square yard, including main¬ 
tenance for five years, is about $2.98. 

The prices per square yard given in Table XXXV for American 
cities includes in nearly all cases the maintenance of the pavement 
for a period of five years. 

The extent of the asphalt pavement in use in 1890 was: United 
States, 6,803,054 square yards, equal to 446 miles of roadway 26 feet 
wide; Europe, 1,698,846, equal to 111.3 miles. 

233. Cost of Maintenance. —Asphalt pavements are generally 
maintained by the companies that construct them. The systems 
adopted are as follows: 

The company constructing the pavement undertake to maintain 




142 


HIGHWAY CONSTRUCTION. 


TABLE XXXY. ' • 

Extent and Cost op 1 Asphalt Pavements in the Principal Cities 

op 1 the United States in 1890. 


Cities. 

Extent. 

Miles. 

Cost of Construction 
per square yard. 

Buffalo, N. Y. 

83.00 

$3.00 

Washington, D. C. 

49.70 

Philadelphia, Pa... 

24.60 

2.50 

Omaha, Neb. 

15.75 

2.98 

Brooklyn, N. Y. 

8.82 


Rochester, N. Y. 

8.00 


Detroit, Mich. 

6.86 

3.30 

Utica, N. Y. 

6.14 


St. Joseph, Mo. 

6.00 

2.80 

Erie, Pa... 

Chicago, Ill. 

5.58 

3.00 

5.09 

3.00 

Toledo, Ohio. 

4.50 

2.58 

St. Paul, Minn. 

4.04 

2.75 

St. Louis, Mo. 

3.95 

2.97 

New York, N. Y. 

3.36 

3.25 to 4.50 

Boston, Mass . .... 

2.70 

3.50 

Harrisburg, Pa. 

2.50 

2.78 

Syracuse, N. Y. 

1.79 

2.70 

Minneapolis, Minn. 

0.98 

2.75 

Providence, R. I. 

0.84 

2.50 

Schenectady, N. Y. 

0.75 

Newark, N. J. 

0.57 

2.80 

Troy, N. Y. 

0.50 


Albany, N. Y. 

0.46 


Los Angeles, Cal. 

0.30 

2.56 

New Haven, Conn. 

0.25 

2.75 

Grand Rapids, Mich. . 

0.21 

2.95 

Milwaukee, Wis. 

0.16 

2.65 

^Montreal, Cau. . 


( 3.43 
( 3.97 

^Toronto, Can. 

5.08 

3.00 

^Berlin, Ger. 

45.00 

3.50 

*London (city). 

13.00 

3.75 to 4.50 

*London (vestries). 

10.00 

< < «< 

*Paris, France. 

22.50 

4.00 to 4.30 


* Foreign cities for comparison. 


Since the above table was compiled there has been considerable fluctuation 
in the prices. In 1895 the prices bid in New York ranged from $3.06 to $4.43 
per square yard. 

In Brooklyn, N. Y., for an asphalt pavement consisting of one inch of coal- 
tar binder laid over the surface of cobblestone pavements and a 2-inch surface 
coat of asphalt, the following prices were bid (1895): 

Alcatraz, $1.44. Trinidad (lake), $1.60-$1.69. Trinidad (land), $1.35. 
European rock asphalt, $1.45-$1.60. Bermudez, $1.97. 

In Buffalo for Kentucky rock asphaltum $1.65 was bid. 














































ASPHALTUM AND COAL-TAR PAVEMENTS. 


143 


it in good condition for a fixed number of years. In America the 
cost of maintenance is included in the price paid for the construc¬ 
tion, and the period varies from five to fifteen years. 

In Europe a fixed price is paid for construction, and the com¬ 
pany maintain the surface free for two years, after which period 
they are paid a certain amount annually per square yard, depending 
upon the amount of the traffic over the pavement, for maintaining 
it in good condition (usually fifteen years); in case of any disturb¬ 
ance of the pavement by a corporation or by a private citizen, the 
company replaces the pavement at the expense of such corporation 
or citizen, and is responsible for the maintenance thereafter. 

A force of men is kept constantly at work making repairs, and 
any defect, however slight, is repaired immediately. 

It is not considered that the necessity for continual repairs is 
an evidence of poor workmanship in the original construction or of 
defective materials used, but rather that an earnest endeavor is 
being made to keep the pavement, even under heavy traffic, at all 
times in perfect order. This prompt and constant repairing 
explains the superior condition of the pavements in the cities of 
Europe. 

234. The average cost of maintaining asphalt pavements in 
London for an average of fifteen years is as follows: 

Yal de Travers. 24 cents per annum 

Limner. 19 

Societe Fran 9 aise . 22 

The average cost in America is placed at 10 cents per square 
yard per annum. 

235. In St. Louis, Mo., maintenance under contract varies between 

and 9 cents per square yard per annum, the period contracted 

for being ten years,—the first year at the cost of the contractor. 

The cost of maintaining the asphalt pavements of Washington, 
D. 0., is stated to vary from to 2 cents per square yard, per 
annum. 

In 1893 the cost ot resurfacing was $1.50 per square yard, guar¬ 
anteed as a new pavement for a period of five years; the cost of 
repairs per square yard was 2.8 cents. 

In Buffalo the average cost per square yard for repairs, based 






144 


HIGHWAY CONSTRUCTION. 


on the whole quantity under maintenance, is 5 cents; based on the 
number of yards contained in the streets actually repaired, the 
average is 7^ cents. Resurfacing costs $1.40 per square yaid, and 
skimming, that is, heated with a surface heater and smoothed, costs 
99 cents. 

236. In Paris the asphaltic pavements cost about 40 cents per 
square yard per annum to maintain, including the chaige foi le- 
newing y-g- part of the surface every year. 

237. Mr. Elliot C. Clarke gives the following as the cost per 
square yard per annum of Yal de Travers compressed asphalt under 
an annual traffic tonnage of 100,000 tons per yard of width. 


Interest on original cost. 19.4 cents 

Maintenance per square yard. 7.2 

Scavenging per square yard. 0.8 


Total. 27.4 cents 


Nothing is charged for renewal, as the annual sum for mainte¬ 
nance provides for the asphalt in perpetuity. 

238. In Omaha, Neb., the cost of maintenance, after the ex¬ 
piration of the guarantee period, is 8 cents per square yard, under 
a ten years* contract. 

239. In Berlin, the cost of maintenance for twenty years is 
fixed by contract at $1.50 per square yard. 

240. Foundation.—A solid unyielding foundation is indispens¬ 
able with all asphaltic pavements, because asphalt of itself has no 
power of offering resistance to traffic; consequently, if the founda¬ 
tion is not thoroughly solid and unyielding the weight of the traffic 
will crush it, and the asphalt will give way in all directions and go 
to pieces. Two classes of foundation are used: (1) Hydraulic 
cement concrete; (2) Bituminous concrete. 

Recently, with the object of reducing the cost of construction, 
the asphaltic paving composition has been laid upon the surface of 
old macadam, cobble, and stone-block pavements, and the results 
seem to be equally satisfactory as with the concrete foundations. 

241. Each class of concrete has its advantages and disadvan¬ 
tages: with cement concrete, the bond between the foundation and 
the wearing surface is not very great, hence it is very easy to strip 
off the surface in case repairs are necessary; but, on the other hand,. 











ASPHALTUM AND COAL-TAR PAVEMENTS. 


145 


the surface sometimes slips on the foundation, and under traffic 
rolls into waves and irregular surfaces, and sometimes cracks with 
sudden and great changes of temperature. A cement concrete 
foundation must be set and thoroughly dry before the asphalt is 
laid; the best asphalt laid in the most skilful manner on first-class 
but damp concrete will rapidly go to pieces. When the hot asphalt 
is applied to a damp surface the water is immediately sucked up 
and turned into steam, which tries to escape through the heated 
material; the result is that coherence is prevented, aud, although 
the surface of the asphalt is smooth, the mass is really disintegrated 
from underneath by its bitter enemy, "water.” As soon as the 
pavement is subjected to the action of traffic, the fissures formed by 
the steam appear on the surface, and the whole pavement quickly 
falls to pieces. For the same reason asphalt should be laid only in 
dry weather. 

242. With bituminous concrete the foundation and wearing 
surface are united into one mass and cannot be easily separated. 
Repairs are difficult, but waving and cracking are less frequent, and 
the bituminous concrete is less expensive. 

243. Asphalt Cement Pavements are composed of two essential 
parts, the matrix and the aggregate, and the success or failure of 
the pavement will depend upon the care exercised in selecting the 
materials and the skill displayed in combining them and laying the 
pavement. 

244. The matrix consists of cement prepared from some selected 
asphaltum in the manner described in Art. 96. Its propor¬ 
tion varies from 10 to 15 per cent, according to the character of 
the aggregate, climate of the locality where used, amount and char¬ 
acter of the traffic. In cold climates more cement is required than 
in warm ones; pavements subject to constant and heavy traffic re¬ 
quire less cement than those used by light traffic. 

245. The aggregate consists of sand and stone-dust. 

246. In quality the sand should be equal to that used for the 
best quality of hydraulic cement mortar; it must be free from loam 
and vegetable impurities; its character should be angular grains 
ranging from coarse to fine. (See also Art. 252.) 

247. The stone-dust is used to aid in filling the voids in the 
sand and thus reduce the amount of cement required for this pur¬ 
pose (the voids in sand range from 0.30 to 0.50 per cent). The 




14G 


HIGHWAY CONSTRUCTION. 


amount used will vary with the coarseness of the sand and quality 
of the cement. The proportion used ranges from 5 to 15 per cent. 

248. As to the quality of the stone-dust; that from any durable 
stone is equally suitable. Limestone-dust was originally used and 
has never been entirely discarded, although it may be one of the 
weak elements in the composition; for carbonate of lime, though 
practically insoluble in pure water, is decidedly soluble in water 
containing carbonic acid gas. As rain-water contains this gas in 
absorption, its action upon the lime in the pavement is to slowly 
dissolve it, and thus expose the cement to the oxidizing action of 
the atmosphere. Organic and weak acids such as are found on 
streets also decompose the lime. 

249. The paving composition is prepared by heating the mixed 
sand and stone-dust and the asphalt cement separately to a tem¬ 
perature of about 300° F. The heated ingredients are measured 
into a pug-mill and thoroughly incorporated; when this is accom- 
l^lished, the mixture is ready for use. It is hauled to the street in 
iron carts, the interior surface of which is previously painted with 
petroleum oil to prevent it from sticking; it is spread with iron 
rakes to such depth as will give the required thickness when com¬ 
pacted (the finished thickness varies from 14 to 2 4 inches; the re¬ 
duction of thickness by compression is generally about 40 per cent). 

250. The compression is accomplished by means of rollers and 
tamping-irons, the latter being heated in a fire contained in an iron 
basket mounted on wheels ; these irons are used for tamping such 
portions as are inaccessible to the roller, viz., gutters and around 
manhole heads, etc. Two rollers are generally employed—one a 
hand-roller weighing about 800 pounds, the other a steam-roller 
of the form shown in Chap. XXIII, ranging in weight from 
5 to 10 tons. The surface of the hand-roller is painted with 
kerosene to prevent the mixture from sticking to it, and is 
generally propelled by four or more men walking on the surface 
of the heated paving mixture. The hand-roller is being super¬ 
seded by heating the front roll of the steam-roller; the heating is 
effected either by fire carried in an iron basket suspended from the 
axle inside the roller, or by an attachment for using steam from the 
boiler. Two steam-rollers are sometimes employed, one weighing 
from 5 to 6 tons and of narrow tread—this is used to give the first com- 



ASPHALTUM AND COAL-TAR PAVEMENTS. 


147 


pression; and the other, weighing about 10 tons and of broad tread, 
is used for finishing. The amount of rolling varies; the average ap¬ 
pears to be about one hour per one thousand square yards of pave¬ 
ment. After the primary compression by either the hand or 
heated roller natural hydraulic cement or any impalpable mineral 
matter is sprinkled over the surface to prevent the adhesion of the 
material to the cold roller and to give the surface a more pleasing 
color. To prevent rotting of the paving material in the gutters 
they are formed of either hydraulic cement, granite blocks, vitri¬ 
fied brick, etc., or when the asphaltic material is laid up to the 
curb the surface of the portion forming the gutter is painted with 
a coat of hot asphaltic cement. 

251. The paving composition is usually spread upon the foun¬ 
dation in two layers; the first is called the “binder” or "cushion 
-coat”; it contains from 2 to 5 per cent more cement than the sur¬ 
face layer; its finished thickness varies from one half to one and one- 
half inches. The object of the binder is to unite the surface mixture 
with the foundation, which it does through the larger percentage 
of cement that it contains, and which if put in the surface mixture 
would render it too soft. When the " binder ” has been compressed, 
it is ready to receive the surface coat, which is laid and compressed 
as above described. When bituminous concrete is used as the foun¬ 
dation, the " binder” is omitted. When the pavement is to be laid 
upon the surface of an old pavement, the binder or cushion coat is 
used to fill up the inequalities and bring its surface to the uniform 
grade and contour. 

252. Failure of Asphaltic Cement Pavements.—The failure of 
this class of pavement may be attributed to any one or all of the 
following causes: 

(1) Unsuitable asphaltum. (That is, asphaltum which has been 
so changed by natural causes as to possess little or no cementing 

power.) 

(2) Too high temperature in refining the crude asphaltum. (That 
is, a temperature which converts the petrolene or cementing me¬ 
dium of the asphaltum into asphaltene and thus reduces or entirely 
destroys its cementing qualities.) 

(3) Too low a temperature continued for a considerable length of 
time. (This has the same effect as a high temperature for a short 





148 


HIGHWAY CONSTRUCTION. 


time, and is analogous to the action of solar heat, which through 
ages has been changing the liquid bitumen wherever exposed into 
asphaltum.) 

(4) Unsuitable fluxing agents . (Such as those which are not 
solvents of the asphaltene and thus form a mechanical instead of a 
chemical union, or fluxes which contain volatile oils, which under 
the action of solar heat evaporate from the pavement and leave it 
porous and in a condition to absorb rain-water, the oxidizing 
action of which is to gradually convert the petrolene or cementing 
agent of the bitumen into asphaltene, thus rendering the pavement 
brittle, in which condition it is easily broken up under the action of 
the traffic.) 

(5) Unsuitable temperature employed during the process of flux¬ 
ing. (That is, either a high temperature for a short time or a low 
one for a long time, the effects of which are similar to those stated 

under 2 and 3.) 

' 0 

(G) Unsuitable sand. (That is, sand either too coarse or too fine, 
or a sand of suitable fineness, but containing loam, vegetable matter 
or clay. The sand should be clean, sharp, large-grained, and not too 
uniform in size, well screened and if necessary washed. The presence 
of clay prevents that intimate contact between the cement and the 
grains of sand so essential to a homogeneous body, because the 
particles of clay adhere to the grains of sand and form diaphragms 
between it and the cement. The sand imparts crushing strength 
and fulfils practically the same offices as in hydraulic cement mor¬ 
tar, therefore its quality should be in all respects equal to that 
used in the best mortar for important structures.) 

(7) Use of limestone-dust. (This material is speedily dissolved 
by rain-water and some of the organic acids found in streets; its 
dissolution leaves the pavement in the same condition and exposed 
to the same agent of destruction as described under cause 4.) 

(8) Insufficient mixing of the ingredients. (Whereby the ce¬ 
ment and the particles of sand are not brought into intimate 
contact; to secure a strong mortar or concrete it is essential that 
each piece of the aggregate shall be entirely surrounded by the 
cementing material, so that no two pieces are in actual contact.) 

(9) Insufficient quantity of cement. (The quantity of cement 
required to coat each particle of the sand will vary with the char- 



ASPHALTUM AND COAL-TAR PAVEMENTS. 


149 


acter of the sand; if the grains in a given volume are small, the 
magnitude of the total surface to he covered is greater than when 
the grains are large; hence a fine sand requires more cement than a 
coarse one; therefore the proportion of the cement must be varied 
to suit the character of the sand to be used, or else the quality of 
the pavement will be impaired.) 

(10) Laying the paving composition on a wet foundation. 
(When hydraulic concrete is used as the foundation, it must be set 
and thoroughly dry before the asphalt is laid upon it; if not, the 
contained water will be sucked up and converted into steam, which 
tries to escape through the heated material; the result is that co¬ 
herence of the asphaltic mixture is prevented, and, although its 
surface may be smooth, the mass is really honeycombed, and as soon 
as the pavement is subjected to the action of traffic the voids or 
fissures formed by the steam appear on the surface, and the whole 
pavement is quickly broken up.) 

(11) Weak or insufficient foundation. (A weak or improperly 
prepared foundation will, by unequal settlement and settlement in 
spots, cause cracks and depressions in the asphalt surface which 
under traffic will be speedily enlarged, and the pavement will there¬ 
fore be broken up.) 

(12) Use of paving mixture which has become chilled. (Al¬ 
though asphaltum is a bad conductor of heat, and the cement re¬ 
tains its plasticity for several hours, occasions may and do arise 
through which the composition before it is spread or rolled has 
cooled; its condition when this happens is analogous to hydraulic 
cement which has taken a “set,” and the same rules which apply 
to hydraulic cement in this condition should be respected in regard 
to asphaltic cement.) 

(13) Insufficient compression. (To prevent the admission of the 
rain and other water falling upon the surface of the pavement, and 
its destroying effects, it is necessary that the paving composition be 
compacted into a solid homogeneous mass; if not, the oxygen con¬ 
tained in the water will have the effect described under cause 4.) 

(14) Lack of water-tight connection with street furniture, curbs, 
and crossings, which permits the entrance of water under the as¬ 
phaltic surface. 

(15) Destruction by natural causes . (All materials in nature are 




150 


HIGHWAY CONSTRUCTION. 


undergoing changes due to the action of the elements, and asphal- 
tum is no exception. Under the action of solar heat and water all 
the bitumens undergo a change; this change is due to evaporation,, 
volatilization, and oxidation, and tends at first to greater solidifi¬ 
cation or hardness. When the maximum degree of hardness is at¬ 
tained, natural decay apparently commences, and under the com¬ 
bined action of organic acids, rain-water, and frost the material 
seems, so to speak, to rot and finally disintegrate. At any stage of 
the change the substance is still asphaltum and the process is 
termed “ ageing,” and a great deal of the controversy regarding 
the relative qualities of different asphaltums is due to ignoring the 
changes wrought by nature. While these changes are slow in 
nature, some or all of them may be hastened by the unskilful appli¬ 
cation of artificial heat in preparing the material, and by the action 
of the organic acids and rain-water falling upon the pavement. 

253. Trinidad Asphalt Pavements.—The source of the asphal¬ 
tum used in this class of pavement is described in Art. 100. The 
characteristics of the crude asphaltum are given in Art. 10(M. 

The method of refining is described in Art. lOOe. 

The characteristics of the refined asphaltum are given in Art.. - 
100^, and the relative qualities of “lake” and “land” asphaltum 
are discussed in Art. 100/;. 

The paving material consists of silicious sand and stone-dust 
(usually limestone) cemented together with asphaltic cement, man¬ 
ufactured as described in Art. 9G. The proportions of the ingre¬ 
dients are not constant, but vary with the climate of the place 
where the pavement is to be used, the character of the sand, 
and the amount and character of the traffic that will use the pave¬ 
ment; the range in the proportions is as follows : 

Asphalt cement. 12 to 15 per cent. 

Sand. 83 to 70 “ 

Stone-dust.„. 5 to 15 “ “ 

100—100 

The sand and asphaltic cement are heated separately to about 
300° F. The stone-dust (pulverized carbonate of lime) is added to 
the hot sand in the required proportions, and is then mixed with 
the hot asphaltic cement in a suitable mixing machine and thor- 







ASPHALTUM AND COAL-TAR PAVEMENTS. 


151 


°ughly incorporated; when this is accomplished, the mixture is 
ready to be laid on the street. 

Specifications for Trinidad asphalt pavements are given in Ar¬ 
ticles 262, 263, and 264. 

254. The proportions of the materials for the Trinidad asphalt 
pavements at Washington, D. 0., average as follows: 


Weight of— 

Cranford. 

Barber. 

Pounds. 

Per cent. 

Pounds. 

Per cent. 

Sand. 

584 

75.0 

637 

74.3 

Stone dust. 

54 

6.9 

60 

7.0 

Limestone dust. 

30 

3.8 

35 

4.1 

Asphalt cement. 

111 

14.3 

125 

14.6 


255. Analyses of selected samples of the above composition are 
made daily. There is, of course, some variation in the amount of 
bitumen in the samples, but it is very small. Out of 17 samples 
taken at different times on one day only 3 showed deviations 
of more than 0.2 per cent from the average. Slightly more 
asphalt is used in winter than in summer. 

256. A cubic yard of the prepared material weighs about 4500 
pounds and will lay the following amount of wearing surface: 

2 i inches thick. 12 square yards 

2 “ “ . 18 

14 “ “ . 27 “ 

257. One ton of the refined asphaltum makes about 2300 pounds 
of asphaltic cement, equal to about 3.4 cubic yards of surface 
material. 

258. Extracts from the Reports of City Civil Engineers.— 
Washington, D. C. (Capt. Greene, 1885).—The Trinidad asphalt 
has been the standard pavement for the last seven years, about 
600,000 square yards having been laid on a foundation of hydraulic 
concrete, and about 160,000 yards more on the stone foundations 
of the worn-out tar pavements. Its cost for the last three years 
has been about $2.25’ per square yard. When made with skilled 

























152 


HIGHWAY CONSTRUCTION. 


labor and laid under proper supervision it seems to answer all the 
requirements of a first-class pavement in this city. It is almost 
noiseless, not slippery, under ordinary conditions offers little resist¬ 
ance to traction, is easily repaired and cleaned, and is very dur¬ 
able. Large numbers of streets have been laid five, six, and seven 
years, and are in perfect order, although not a cent has been ex¬ 
pended on them for repairs. On other streets mistakes have 
occasionally been made in the mixture, and defects have appeared 
which needed repairs. Nearly all these repairs have been made at 
the contractor’s expense during his guarantee period; but as nearly 
as it can be ascertained the total expense both to contractors and 
the District for repairing asphalt pavements during the eight years 
since they were first laid has been about $30,000, or $3750 per year, 
so that the average annual expense for maintenance up to date has 
been T 9 ^ of one cent per yard per year. This is certainly a small 
expense for the luxury of smooth pavements, and much less than 
for any other pavement having the combined durability and smooth¬ 
ness of the asphalt. 

259. The French Asphalt Pavement , made from the natural 
bituminous limestone of Switzerland, and similar in every respect 
to the asphalt pavements as laid in Paris, was tried here in 1873 
and 1876, 31,388 yards having been laid on the following streets, 
viz.: Pennsylvania Avenue, between First and Sixth streets; I Street, 
betwen Thirteenth and Fifteenth streets; and Grant Place, between 
Ninth and Tenth streets. Experience has shown that this pavement 
is more slippery than the pavement of sand and Trinidad asphalt, 
and that it is not quite as durable. Its cost is nearly fifty per cent 
greater; for these reasons no more of it has been laid. 

260. Buffalo, N. Y. —The streets paved with asphalt have stood 
the extreme changes of this climate without any serious defect, 
are giving satisfaction to our people, being healthful, easily kept 
clean, smooth, yet not slippery. 

261. Omaha, Neb. —“Our temperature varies as much as 150 
degrees Fahr., between the extremes of summer and winter. We are 
subject to rapid changes of temperature, which in the winter season 
occasionally are as high as 60 degrees in twenty-four hours. Doug¬ 
lass Street, which was paved in the fall of 1882 and spring of 1883, 
has experienced a range of temperature of from 120 degrees in the 
summer to 34 degrees below zero in the winter. . . . Our experience 





t 


ASPHALTUM AND COAL-TAR PAVEMENTS. 153 

is very favorable to asphalt pavements on all grades ranging from 
6 inches to 4 feet rise per 100 feet, and I am not sure but that as 
high as 5 or G feet per 100 feet may be favorably overcome. The 
asphalt pavement is not as cheap as wood, but, in my opinion, a 
preferable pavement upon permanently established and well-im¬ 
proved streets. It is not quite as easy for horses as wood, but more 
comfortable for those who ride, is more cleanly, and from a sanitary 
standpoint far superior.” 

262. Heads of Specifications for Standard Trinidad Asphaltum 
Pavements. 

(1) Preparation of Roadbed. 

(2) Foundation. (Hydraulic-cement or bituminous concrete.) 

(3) The Wearing Surface will be composed of 

(a) Refined Trinidad asphaltum. 

(b) Heavy petroleum oil. 

(c) Find sand containing not more than one per centum 

of hydrosilicate of alumina. 

(d) Fine stone-dust. 

(e) Fine powder of carbonate of lime. 

(4) Preparation of the Asphalt. —The Trinidad asphaltum shall 
be refined, and as far as possible freed from foreign organic and 
animal matter and volatile oil, and brought to uniform standard of 
purity and gravity, containing not less than 60 per cent of bitumi¬ 
nous matter soluble in bisulphide of carbon. The asphaltum must 
be refined under the direction and to the satisfaction of the engineer, 
and kettles will not be drawn lower than may be ordered by him. 

The heavy petroleum oil shall be freed from all impurities and 
brought to a specific gravity of from 18 to 22 degrees Beaume and 
a fire test of 250 degrees Fahrenheit. 

From these two hydro carbons shall be manufactured an 
asphalt cement which shall have a fire test of 250 degrees Fahr., 
and at a temperature of GO degrees Fahr. shall have a specific 
gravity of 1.19, said cement to be composed of 100 parts of pure 
asphalt and from 15 to 20 parts of heavy petroleum oil. 

(5) Manufacture of the Paving Material.— The asphalt being- 
prepared in the manner abo\e described, the pa\ement nnxtuic 
will be formed of the following materials, and in the proportions 

stated. 



154 


HIGHWAY CONSTRUCTION. 


Asphaltic cement.from 12 to 15 

Sand. “ 83 “ 70 

Pulverized carbonate of lime. “ 5 “ 15 

or 

Asphaltic cement.from 13 to 16 

Sand . “ 63 “ 58 

Stone-dust.. “ 28 “ 23 

Pulverized carbonate of lime. “ 3 “ 5 


The proportion of the materials will depend upon their char¬ 
acter and the traffic on the street, and will be determined by the 
engineer. If the proportions of the mixture are varied in any 
manner from those directed to be used, the mixture will be con¬ 
demned ; and if already placed on the street, it will be removed and 
replaced by proper material, at the expense of the contractor. 

The sand, stone-dust and asphaltic cement are to be heated sep¬ 
arately to about 300 degrees Fahr. The pulverized carbonate of 
lime while cold shall be mixed with the hot sand and stone-dust in 
the required proportions, and then mixed with the asphaltic cement 
at the required temperature, and in the proper proportion, in a 
suitable apparatus, which will effect a perfect mixture. The pro¬ 
portions will be gauged daily in the presence of the inspectors. 

(6) Quality of the Materials .—All the materials used, as well as 
the plant and method of manufacture, will be subject to the inspec¬ 
tion and approval of the engineer. The degree of fineness, both of 
the sand, stone-dust, and powdered limestone, will be determined 
by testing with screens, as follows: The powdered carbonate of 
lime will be of such degree of fineness that 15 per cent by weight 
shall be an impalpable powder of limestone, and the whole of it 
shall pass a No. 26 screen. The sand will be of such size that 
more than 50 per cent of it will pass a No. 80 screen, and the 
whole of it shall pass a No. 20 screen. The stone-dust shall be the 
residue of granite or other approved stone, and shall pass a sieve of 
not more than 6 meshes to the inch. 

(?) Laying the Asphalt. (Two-coat Pavements.)—The pave¬ 
ment mixture, prepared in the manner thus indicated, shall be laid 
on the foundation in two coats. The first coat, called cushion-coat, 
shall contain from 2 to 4 per cent more asphaltic cement than 
given above; it will be laid to such depth as will give a thickness 
of \ inch after being consolidated by a roller. The second coat,. 










ASPHALTUM AND COAL-TAR PAVEMENTS. 


155 


called surf ace-coat, prepared as above specified, shall be laid on the 
cushion-coat; it shall be brought to the ground in carts at a tem¬ 
perature of about 250 degrees Fahr., and if the temperature of the 
air is less than 50 degrees iron carts with heating apparatus shall 
be used in order to maintain the proper temperature of the mix¬ 
ture; it shall then be carefully spread by means of hot iron rakes, 
in such manner as to give a uniform and regular grade, and to 
such depth that after having received its ultimate compression it 
will have a thickness of 2 inches. The surface then shall be com- 
pressed by hand rollers, after which a small amount of hydraulic 
cement shall be swept over it, and it then shall be thoroughly com¬ 
pressed by a steam roller weighing not less than 250 pounds to the 
inch run; the rolling to be continued for not less than five hours 
for every 1000 yards of surface. 

(8) Laying the Asphalt. (One-coat Pavement.)—The pavement 
mixture, prepared in a manner thus indicated, will be laid on the 
foundation; it will be laid to such depth as will give a thickness of 

inches after being consolidated by rollers. It will be brought 
to the ground in carts, at a temperature of not less than 250 de¬ 
grees Fahr. nor more than 310 degrees Fahr., and if the tempera¬ 
ture of the air is less than 50 degrees the contractor must provide 
canvas covers for use in transit. It will then be carefully spread 
by means of hot iron rakes, in such manner as to give uniform and 
regular grade and to such depth that, after having received its 
ultimate compression of two fifths, it will have a net thickness of 

inches. This depth will be constantly tested by means of 
gauges furnished by the engineer. The surface will then be com¬ 
pressed by hand rollers, after which a small amount of hydraulic 
cement will be swept over it, and it will then be compressed by a 
steam roller weighing not less than 5 tons, to be followed by another 
steam roller weighing not less than 10 tons, the rolling being con¬ 
tinued for not less than 10 hours for every 1000 yards of surface. 

(9) In order to make the gutters entirely impervious to water, 
a width of 12 inches next the curb will be coated with hot pure 
asphalt and smoothed with hot smoothing-irons in order to saturate 
the pavement to a certain depth with an excess of asphalt; oi if bo 
directed by the engineer, the gutters will be formed with gutter- 
stones, granite blocks, or bricks, in accordance with the specifica¬ 
tions for such work. 






156 


HIGHWAY CONSTRUCTION. 


(10) Laying Granite Blochs adjoining Railway Tracks .—■ 
When asphalt pavement is laid in a street containing the tracks of 
a street railroad one row of selected granite paving-blocks will be 
laid next to the track, alternating as headers and stretchers tooth¬ 
ing into the pavement. The foundation will extend to the depth 
of the bottom of the cross-ties, and will be similar in all respects to 
the foundation of the carriageway pavement, except as to the 
thickness of the base. If the foundation consists of bituminous 
concrete, the blocks will be laid directly upon jand embedded in the 
binder while it is still in a hot and plastic condition. If the foun¬ 
dation consists of hydraulic-cement concrete, the base will be cov¬ 
ered with a layer of fine sharp sand, washed and dried, 2 inches in 
thickness, and the blocks will be laid directly upon and embedded 
in the sand with close joints. 

The top of the blocks will be even with the surface of the tread 
of the rail, which shall conform with the grade of the street. The 
blocks will be laid before the asphaltic wearing surface is laid upon 
the carriageway, and carefully rammed to a firm bed. Care will 
be taken to fit them well up against the stringers or web of the rail 
of the railroad. The space back of the blocks will be filled to the 
surface of the base for the carriageway pavement with the same 
material as is used for said base, well rammed. 

Immediately after the wearing surface shall have been laid, 
clean, fine, hot gravel, not larger than one-half inch in any 
direction, will be poured into the joints of the blocks until they 
become nearly filled. There will then be poured into the joints, at 
a temperature of 300 degrees Fahr., paving cement made of No. 6 
coal-tar distillate, until the joints are completely filled flush with 
the surface of the pavement. Additional fine hot gravel will then 
be poured along the joints, and will be consolidated by tapping 
with a light rammer. If found necessary additional paving cement 
will be poured between the blocks until the joints are thoroughly 
filled. 

In measuring this work for payment, when standard size gran¬ 
ite blocks are used, the area included between the outer edsre of 
the rail and a line parallel to and six inches from rail will be taken 
as the area of granite-block pavement laid. Bids will be based on 
this rule. When so ordered, the block pavements will be extended 
to cover the entire area included between the rail and parallel to 





ASPHALTUM AND COAL-TAR PAVEMENTS. 


157 


and 2 feet distant from said rail. In case the tracks are laid with 
a grooved girder rail, these headers and stretchers may be omitted 
if so ordered by the engineer, and the asphalt pavement laid close 
to the rail. 

(11) The work of laying the asphalt shall not begin until the 
curbstones, crosswalks, catch-basins, manhole beads, etc., have been 
properly adjusted to the finished grade of the street, and permis¬ 
sion to proceed has been received from the engineer. 

(12) Interpretation of specifications. 

(13) Omissions in specifications. 

(14) Engineer defined. 

(15) Contractor defined. 

(1G) Notice to contractors, how served. 

(17) Preservation of engineer's marks, etc. 

(18) Dismissal of incompetent persons. 

(19) Quality of materials. 

(20) Samples. 

(21) Inspectors. 

(22) Defective work, responsibility for. 

(23) Measurements. 

(24) Partial payments. 

(25) Commencement of work. 

(26) Time of completion. 

(27) Forfeiture of contract. 

(28) Damages for non-completion. 

(29) Evidence of the payment of claims. 

(30) Protection of persons and property. 

(31) Indemnification for patent claims. 

(32) Indemnity bond. 

(33) Bond for faithful performance of work. 

(34) Power to suspend work. 

(35) Eight to construct sewers, etc. 

(36) Loss and damage. 

(37) Old materials, disposal of. 

(38) Cleaning up. 

(39) Personal attention of contractor. 

(40) Payment of workmen. 

(41) Prices. 

(42) Security retained for repairs. 

(43) Payment when made, final acceptance. 



158 


HIGHWAY CONSTRUCTION. 


263. Specifications for Asphalt Pavement on Bituminous Base.— 

Combination asphalt pavement on bituminous base will consist of 
a base 4 inches, a binder of 1\ inches, and a wearing surface of 1J 
inches in thickness, when compacted. 

The space over which the pavement is to be laid will be ex¬ 
cavated to the depth of 7 inches below the top of the surface of the 
pavement when completed. Any objectionable or unsuitable ma¬ 
terial below the bed must be removed, and the space filled exactly 
parallel to the surface of the new pavement when completed; and 
the entire roadbed will be thoroughly rolled with a heavy steam¬ 
roller weighing not less than 5 tons. Upon the foundation will 
be laid the base and binder, 5|- inches in thickness, in the following 
manner: 

Base .—The base will be composed of clean broken stone that 
will pass through a 3-inch ring, well rammed and rolled with a 
steam-roller weighing not less than 5 tons, to a depth of 4 inches. 
The rolling will be continued until the stone ceases to creep before 
the roller, and until it is evident that the final compression has 
been reached. It will be thoroughly coated with No. 4| coal-tar 
paving cement in the proportion of about one gallon to the square 
yard of base. 

Binder .—The second or binder course will be composed of 
clean broken stone, thoroughly screened, not exceeding 1 inch in 
the largest dimension, and No. 4 coal-tar paving-cement. The 
stone will be heated to a temperature between 230 and 250 degrees 
Falir., by passing through revolving heaters, and thoroughly mixed 
by machinery with the paving-cement in about the proportion of 
one gallon of No. 4 tar to one cubic foot of stone. It will be 
hauled upon the work, spread upon the base course to such thick¬ 
ness that when compacted it will be 1^ inches thick, and immedi¬ 
ately rammed and rolled with hand and steam rollers while in a 
hot plastic condition. 

Wearing Surface .—The wearing surface will be 1J inches thick 
when compacted, and will conform in all other respects to the 
wearing surfaces as prescribed for the standard asphalt pavement, 
as described in these specifications. 

The pavement so constructed must be a solid mass, 7 inches 
thick, and must be thoroughly rolled and cross-rolled until it has 
become hard and solid. 






ASPHALTUM AND COAL-TAR PAVEMENTS. 


159 


Gutters, wherever directed, will be formed of granite-block or 
brick, of such width as may be directed, laid upon a hydraulic base 
of not less than 4 inches in thickness, in accordance with the speci¬ 
fications for granite-block pavement and for brick gutters. 

264. Specifications for Asphalt Pavement on Hydraulic Base.— 
The asphalt pavement on hydraulic base will be 7 inches in thick¬ 
ness, consisting of a base composed of 4 inches of hydraulic con¬ 
crete and 2 inches of binder, 1| inches when compacted, and a 
wearing surface of standard asphalt, 2J inches in thickness, or 1J 
inches when compacted. 

Binder Course .—The binder course will conform in all respects 
to the binder course for the asphalt pavement on bituminious base, 
and will be 1J inches in thickness when compacted. 

Wearing Surface .—The wearing surface will be 1| inches thick 
when compacted, and will conform in all other respects to the wear¬ 
ing surfaces as prescribed for the standard asphalt-pavement. 

264a. Specifications for Asphalt Pavement on the Surface of an 
Old Pavement.—The surface of the old pavement shall be thor¬ 
oughly cleansed by sweeping with stiff brooms until all the dirt, etc., 
has been removed from the surface and from the joints to a depth 
of about one inch. 

The surface shall then be brought to a uniform grade and cross- 
section by excavating where necessary, and by filling and repairing 
all depressions with bituminous concrete or binder, this binder to 
be composed of clean broken stone, the fragments of which shall 
not exceed one and one quarter inches in their largest dimensions, 
and asphaltic pavement cement (or coal-tar paving-pitch). 

Idle stone shall be heated in suitable heating apparatus, and 
shall be thoroughly mixed with the paving cement in the propor¬ 
tion of 12 to 15 per cent of asphalt paving cement (or one gallon 
of paving-pitch) to one cubic foot of stone. 

This binder shall be spread to such thickness that, after being 
thoroughly compacted by tamping and rolling, its thickness shall 
be not less than one inch, and its surface shall be exactly parallel 
with the surface of the pavement to be laid upon it. 

Upon this foundation the wearing surface or pavement proper 
of asphaltic cement shall be laid. (See also Articles 262, 263,264.) 

265. Maintenance of Asphalt Pavements under Contract.—The 
contractors will furnish all the labor and materials necessary to 




160 


HIGHWAY CONSTRUCTION. 


make repairs and renewals required to preserve the surface in a 
perfect state, true to the profile, without humps or depressions,, 
even if the dilapidations are the result of accidental causes, as sink¬ 
ing of the subsoil, etc., except only the digging of trenches. The 
contractor must renew all places where the surface is cracked, split, 
depressed, swelled, or in any way perforated, where it matches un¬ 
evenly with manhole heads and other street fixtures, etc., and 
especially where sunken near trenches. 

Where the foundation is defective, it shall be removed and re¬ 
placed with good material. Defective spots must be carefully cut 
out with a sharp tool, and at least 2 feet larger in every direction 
than the defective place; the sides must be cut on straight lines ; 
there must be a perfect union of the old and new material, and the 
surface must show no irregularities. 

On September 1st, or sooner in case of bad weather, a general 
examination will be made with the contractor, who must immedi¬ 
ately begin repairs on doubtful surfaces, not likely to endure 
through the winter. In rainy weather the bottoms of patches 
must be sponged and dried as carefully as possible with fine hot 
ashes, and then be well brushed. Special care must be taken to 
clean all sand, powder, etc., from the bottom of patches. 

During bad weather no repairs shall be made to the asphalt, 
unless expressly authorized by the engineer. Patches made during 
winter are to be considered as only temporary, and must be replaced 
by the 15th of May. 

The contractor is absolutely forbidden to use pebbles for filling 
holes in the asphalt. When the contractor fails to make the neces¬ 
sary repairs, and the administration, exceptionally and in default 
of other available means, fills the holes with broken stone or other 
material, the contractor must pay for the work and materials, and 
cannot claim damages for injury to the pavement caused by such 
materials. 

In winter, holes in the foundation may be filled with a mixture 
of 3 parts by volume of pebbles to 1 part of hot asphalt; but this 
provisional filling must be removed as soon as possible and replaced 
in the standard manner. 

The contractor will be paid for repairs to all trenches opened in 
the street. He can, however, make no claim for settlement or any 
other injury at these places, and must maintain the pavement there¬ 
in the same condition as elsewhere. 




ASPHALTUM AND COAL-TAR PAVEMENTS. 


161 


To secure a perfect welding at the edges of the asphalt, a width 
of 2 inches greater in every direction than the trench will be 
paid for. 

To provide for settlement of the earth in the trenches, the con¬ 
tractor may maintain the area occupied by the trench, during a 
period of eight days, with broken stone or gravel, well rammed, 
sprinkled, swept, and maintained, so as to prevent injury to horses. 
If after eight days final repairs are still impossible, the contractor 
must art his own expense make a provisional surface of bituminous 
concrete, which will be removed for final repairs. 

If for any reason it becomes necessary to tear up asphalt pave¬ 
ments, it shall be done as follows: It will be cut in as straight lines 
as possible with sharp chisels, and when torn up must on no ac¬ 
count pull up with it any of the adjacent material. 

Then the concrete is to be cut by sharp chisels in lines about 3 
inches from the edge of the asphalt, which may be broken into 
pieces and laid aside. 

In removing the earth from the excavation, care must be taken 
that no portion of the concrete is undermined. 

265a. The “ Bermudez ” Asphalt, recently introduced for paving 
purposes, is obtained from a lake or deposit which covers an area 
of several hundred acres in the state of Bermudez, Venezuela, 
S. A. (See also Art. 101.) 

The purity and quality are said to be exceedingly high; the fol¬ 
lowing analysis is given by Prof. E. J. De Smedt: 


Bitumen soluble in CS 2 . . 97.86 per cent 

Organic and inorganic matter (impurities). 2.14 


100.00 per cent 

The following are some of the characteristics of this asphalt : 

At 60° F. compressible; at 70° F. viscous and malleable; at 
100° F. flowing, and can be stretched in hair-like threads; at 
189° F. melts; at 400° F. gives no flash. 

The paving-cement is manufactured by adding 15 lbs. of re¬ 
siduum oil, 20 Baume at 60° F., to each 100 lbs. of refined asphalt. 
This 100 lbs. of refined asphalt yields 97.06 lbs. of pure bitumen; 
consequently 13 t 3 q per cent of oil is added to the pure bitumen. 

The asphalt is melted at from 250° to 300° F. The oil is then 
added and thoroughly mixed with the melted asphalt. 







163 


HIGHWAY CONSTRUCTION". 


The pavement mixture is composed of the following materials 
and in the proportions stated: 


Asphaltic cement. 9 to 10 parts 

Pulverized carbonate of lime. 20 “ 30 “ 

Fine clean sand. 71“ 60 “ 


100 100 

The sand and carbonate of lime are mixed and heated to 
from 250° to 300° F. The asphaltic cement is heated separately 
to from 225° to 250° F. The materials so heated are mixed in a 
suitable mixing apparatus, and the mixture while at a temperature 
not below 200° F. is spread upon the foundation in two coats, the 
lower or cushion coat being one-half inch thick after compression, 
and the second or wearing coat being two inches thick after final 
compression with a roller weighing not less than 250 lbs. per inch 
run. A small amount of hydraulic cement is swept over the surface 
before the application of the roller. 

It is claimed that pavements made from this asphalt do not rot 
in contact with water. 

One square yard of pavement 2|- inches thick weighs 250 lbs. 

266. European Asphalt Pavements.—In Paris two kinds of as¬ 
phalt pavement are employed. First, asphalt coule , made from 
natural rock asphalt to which is added sufficient bitumen to make 
the total 15 to 18 per cent of bitumen. The mass is heated for about 
six hours so as to make a thorough mixture. The ground having 
been graded, sprinkled and thoroughly rammed or rolled, a bed of 
hydraulic-cement concrete from 4 to 6 inches thick is laid, and after 
this is set and well dried the asphalt mixture is spread and surfaced 
by a wooden float. The thickness of the asphalt is about 1^ inches, 
and it is usually applied in two layers. This covering will not 
soften at a temperature of 140 degrees Fahr. 

267. The second kind of asphalt covering is asphalt comprime, 
or compressed asphalt. In this the natural rock alone is used. It 
comes from Yal de Travers in Switzerland, Seyssel in France, and 
other localities, and consists of carbonate of lime impregnated with 
bitumen. The color is a dark (almost black) chocolate-brown. 
When cold the rock breaks easily, with an irregular fracture and 
without definite cleavage. Its grain should be regular and homo¬ 
geneous; the finer the grain the better. When exposed to the atmos- 








ASPHALTUM AND COAL-TAR PAVEMENTS. 


163 


pliere the bituminous rock gradually assumes a gray tint, by reason 
of the bitumen evaporating from the surface, leaving a thin film of 
limestone behind. 

268. The following is a test for bituminous rock given by 
Mr. Delano in a paper he read before the Institution of Civil En¬ 
gineers in the year 1880. “ A specimen of the rock, freed from all 

extraneons matter, having been pulverized as finely as possible, 
should be dissolved in sulphurate of carbon, turpentine, ether, or 
benzine, placed in a glass vessel and stirred with a glass rod. A dark 
solution will result from which will be precipitated the limestone. 
The solution of bitumen should then be poured off. The dissolvent 
speedily evaporates, leaving the constituent parts of the bitumen, 
each of which should be weighed so as to determine the exact 
proportion. The bitumen should be heated in a lead bath and 
tested with a porcelain or Baume thermometer to 428 degrees Fahr. 
There will be little loss by evaporation if the bitumen is good, but 
if bituminous oil is present the loss will be considerable. Gritted 
mastic should be heated to 450 degrees Fahr. The limestone should 
be next examined. If the powder is white and soft to the touch, it 
is a good component part of asphalt; but if rough and dirty,on 
being tested with reagents it will be found to contain iron pyrites, 
silicates, clay, etc. Some bituminous rocks are of a spongy or hygro- 
metrical nature; thus, as an analysis which merely gives so much 
bitumen and so much limestone may mislead, it is necessary to 
know the quality of the limestone and of the bitumen.” 

The European bituminous limestone appears like a fine-grained 
rock, friable in summer, hard in winter. When heated to 50 or 60 
degrees (centigrade) it can be crushed between the fingers, and if 
exposed for several hours to a fierce sun it crumbles into unctuous 
brown powder. Examined under the microscope it is found to 
consist of minute calcareous grains, each covered with a thin film 
of bitumen which causes them to adhere together. If a small por¬ 
tion is heated, the cementing bitumen is melted and releases the 
solid particles from a loose heap of a deep chocolate color. If 
this powder is raised to 175 or 212 degrees Fahr. and rapidly com¬ 
pressed in a mould, it will regain, in cooling, its original consistency 
in the new form. And the process may be indefinitely repeated, 
no change being produced by melting, followed by compression 
and cooling. 




1G4 


HIGHWAY CONSTRUCTION. 


269. The best material used by the “ Compagnie Generate des. 
Asphaltes de France ” comes from the Pyrimont mines of the 
Seyssel region in the Department of Haute Savoie and Litin, 
France. The workings are in great part subterranean and the 
deposit lies in eight superimposed beds separated by beds of white 
limestone. One of these bituminous beds lies about 100 feet above 
the level of the Rhone and has a thickness of 23 feet; it is the 
largest of all known beds of this material. The galleries now 
driven aggregate about seven miles in length. 

270. The rock is extracted in a temperature ranging from 53 to 
55 degrees Fahr., and it is relatively hard. This desirable quality 
can be increased by taking it outside during the winter,but it should 
not even then be exposed to the sun. Dynamite or gunpowder is 
used in extracting it, the latter being used when the mass is com¬ 
pact, dry, and without fissures. As the rock is to a certain degree 
plastic, it compresses easily and does not work well with the more 
violent and quick explosives. On the other hand, dynamite is 
effectively used in the wetter parts of the mine and in places 
where fissures would permit the slower-acting gases from gunpow¬ 
der to escape without efficient work. 

The blocks of bituminous rock are removed outside by rail and 
as few blocks as possible are piled upon one car, to avoid crushing 
under the effect of the heat of the sun. This crushing is undesir¬ 
able for two reasons: first, there is more waste in the transport and 
handling; and secondly, if rain falls upon a pulverized mass, it ab¬ 
sorbs water rapidly and becomes exceedingly difficult to treat. 

271. The operations preliminary to the application of the bitu¬ 
minous rock to the street surface are: (1) The extraction and (2) 
the crushing of the rock. (3) The heating of the powder. (4) 
Transporting the heated powder to the street. (5) Spreading it 
while warm. (6) Ramming. (7) Rolling. 

272. The quarried blocks of mineral are crushed between 
toothed cylinders, revolving at unequal speeds, which reduce it to 
pieces of the average size of eggs. These are pulverized in “ Can ” 
machines, which run about 600 revolutions per minute, and deliver 
it as powder, which is sifted to uniform extreme fineness. This 
powder is heated in an apparatus resembling a “ coffee-roaster;” 
the revolving cylinder is about 6J feet in diameter and the same in 
length; the exterior envelope carries a chimney, disposed in such 






ASPHALTUM AND COAL-TAR PAVEMENTS. 


165 


fashion that the heated air from the furnace passes all around the 
cylinder. The furnace itself is movable and placed immediately 
below the cylinder, and rests on a railway so that it may be run out 
of the way. The moving cylinder is mounted upon an axle and 
supported on journals in the enveloping cylinder, which rests upon 
four stout legs. 

273. The powder is put into the roaster by means of a hopper 
placed opposite a central hole forming an annular space around 
the axle. The pow r der falls into the cylinder, which is moving very 
■slowly; the cylinder is provided with interior blades arranged in a 
spiral, by which the contents are lifted up to the top and fall in a 
shower through the hot air in the cylinder, until it is thoroughly 
warmed both by this action and by contact with the hot sides of 
the cylinder. As the movement of the cylinder is perfectly regular, 
the pow r der remains on the blades only a determinable time, and 
the entire mass has imparted to it a uniform temperature. The 
apparatus used on the work of the city of Paris heat, to a tempera¬ 
ture of about 300 degrees Fahr., about 3960 pounds of powder 
in 15 minutes. 

When the powder is sufficiently heated the furnace is run out 
from under it, and is replaced by the special wagon used for trans¬ 
porting the warm powder to the place of use, into which the 
powder falls after opening a gate in the side of the cylinder. 

274. Asphaltum is a bad conductor of heat, and this negative 
quality much simplifies the difficulties of its preparation, and per¬ 
mits the material to be heated at central stations and conveyed a 
considerable distance before it will fall appreciably in temperature; 
in fact, the powder loaded into sheet-iron carts with double sides 
and cover may be carried from 1J to 9| miles from the place of 
heating to the place of use without losing on the way more than 
35 or 40 degrees Fahr. of its mean temperature. 

275. The hot material is emptied out on the concrete founda¬ 
tion, spread by hot rakes in a layer of sufficient thickness to allow 
for compression to the exact finished surface and required thick¬ 
ness, viz., about 3 inches for a 2-inch coat. 

The surface, and consequently the thickness, is regulated by a 
wooden straight-edge bearing on parallel guides set at the required 
height in the surface of the concrete. 

276. The ramming is done by round cast-iron rams, 6 to 8 




1G6 


HIGHWAY CONSTRUCTION. 


inches in diameter, which are used by fifteen or twenty men, 
marching side by side and vigorously ramming the asphalt while 
it is yet hot. After a few minutes a roller drawn by two men and 
heated by an internal furnace gives what is called the “ primary 
compression,” the normal compression being effected under the 
traffic by the carriage-wheels. During the rolling a small quantity 
of hydraulic cement is strewn over the surface. The rolling is con¬ 
tinued until the asphalt is cold. 

The bituminous limestone to form a good roadway pavement 
should contain from 9 to 10 per cent of bitumen, and be non-evap- 
orative at 428° Fahr. Limestones containing much more than 10 
per cent of bitumen become soft and wavy in summer; those con¬ 
taining much less have not sufficient binding power to sustain 
heavy traffic. 

277. Bituminous Limestone Pavements in the United States. 

—About 55,000 square yards of bituminous limestone pavement 
were laid in Washington, D. C., during 1876 and 1887, and about 
3000 square yards in New York in 1883 or 1884; nearly all of this, 
was subsequently taken up and replaced by Trinidad asphalt. In 

1887 about 10,000 square yards were laid in Rochester, N. Y.; in 

1888 about 20,000 square yards in St. Augustine, Florida; and in 
1890 40,000 square yards in New York City. The total amount of 
bituminous limestone pavements now in use in the United States 
is estimated at 75,000 square yards. 

These pavements are composed of a mixture of about three 
parts of bituminous limestone rock from Ragusa, Sicily, and one 
part of a similar rock from Vorwohle, Germany; the latter is a 
harder rock and contains less bitumen than the Sicilian. 

The paving mixture contains from 10 to 12 per cent of bi¬ 
tumen, and is prepared by pulverizing the mixed rock and heating 
it to a temperature of about 160° Fahr. The heated powder is laid 
and compressed in the manner described under European Asphalt 
Pavements. 

278. Coal-tar Pavements.—The wearing surface of the earlier 
pavements was made in various ways, according to the patent, but 
consisted essentially of small gravel, sand, and stone-dust, cemented 
by a product of coal-tar. In the later pavements of this variety a 
certain proportion of bitumen is mixed with the tar, and with bene¬ 
ficial results. 






ASPHALTUM AND COAL-TAR PAVEMENTS. 


167 


Wherever laid in the United States, coal-tar pavements, as a rule, 
have given little satisfaction, their failure being due to the pres¬ 
ence of volatile oils in the tar, which on exposure to atmospheric 
influence slowly oxidize and become inert, thus destroying the 
cementing qualities of the tar. If these oils are removed before 
the tar is used the resulting material is brittle, and soon crumbles- 
to pieces after being laid. Coal-tar is also very sensitive to heat: in 
summer it is soft, in winter brittle. On account of these defects, 
the use of coal-tar alone, as a cementing material for pavements, 
has been almost entirely abandoned. 

279. Coal-tar and Asphalt.—To overcome the defects of coal-tar 
when used alone, the practice has arisen of mixing the gas tars with 
bitumen, and this has been successful in proportion to the amount 
of the bitumen used. The most successful pavement of this char¬ 
acter is that known as the “ Vulcanite.” This pavement is prepared 
as follows: 

280. Filbert Vulcanite Asphalt Pavement as laid by the 
National Vulcanite Company of New Jersey.—The pavement is 
inches in thickness, formed as follows: The wearing surface 1^ 
inches when compacted, and a bituminous base and binder 7 inches 
in depth. 

The base is composed of stone broken to pass through a 3-inch 
ring. It is spread on the earth surface, previously graded to receive 
it, to a depth of 5 inches, these consolidated with a steam roller, 
after which it is covered with a hot paving-cement composed of No. 
4 tar distillate in the proportion of about one gallon to the square 
yard of pavement. 

The second or binder course is composed of stone broken to pass 
through a lj-inch ring,—the stone being thoroughly cleansed and 
screened,—and No. 4 tar distillate. The stone is heated by passing 
through revolving heaters, and is thoroughly mixed by machinery 

with the distillate in the proportion of one gallon of distillate to one 

« 

cubic foot of stone. 

The binder is spread upon the base to a depth of two inches, 
and is immediately rammed and rolled with hand and steam rollers 

while hot and in a plastic condition. 

The wearing surface, H inches thick, is made of paving-cement, 
composed of 25 per cent of asphalt and 75 per cent of tar distillate. 



168 


HIGHWAY CONSTRUCTION. 


and clean sharp sand and stone pulverized to pass through a i-inch 
ring in the proportion of two parts of sand to one part of stone. 

To 21 cubic feet of the above ingredients are added one peck of 
hydraulic cement, one quart of flour of sulphur, and two quarts of 
air-slaked lime. To this mixture is added 320 pounds of paving- 
cement. 

The materials above described are heated to about 250 degrees 
Tahr.—the paving cement in kettles, the sand, stone, etc., in revolv¬ 
ing heaters—then thoroughly mixed by machinery, carried to the 
street, and spread on the binder course to a depth of two inches. 
While hot and plastic it is rolled with a steam roller, hydraulic 
cement being dusted over the surface. The rolling is continued 
until the roller ceases to leave an impression on the surface. 

281. Advantages of Coal-tar and Asphalt or Distillate Pavement. 

(1) It is cheap. 

(2) Its surface is more granular and less slippery than asphalt. 

(3) The binder binds the base and wearing surface firmly 
together and eliminates to a great extent the faults of weather 
cracks and wave-surfaces. 

(4) It can be laid from curb to curb, as it will not “ rot” in the 
gutters as does the asphalt. 

(5) Pavements constructed of carefully selected and combined 
materials and properly laid will cost but little, if any, more than 
the asphalt for maintenance. 

282. Defects of Coal-tar and Asphalt Pavement. 

(1) The wearing surface consists of 75 per cent of coal-tar, 
which material can rarely be obtained of uniform quality. 

(2) The wearing surface, being only 1| inches thick, requires 
renewal at frequent intervals. 

(3) The pavement is not so pleasing to the eye as asphalt in 
color. 

(4) The use of the bituminous base gives rise to many per¬ 
plexing problems in the grade of the streets on which it is used, due 
to the fact that the base, the binder, and the wearing surface co¬ 
alesce so as to form a solid mass. The wear on the surface is never 
quite uniform; and when the binder or base becomes exposed on the 
most travelled part of the street, the pavement near the gutter may 
be worn but slightly. To resurface properly, the remnants of the 
old surface should be removed, and the new surface laid directly 


i 






ASPHALTUM AND COAL-TAR PAVEMENTS. 


169 


upon the binder. It is, however, impracticable to strip a coal-tar 
surface. It may be broken by the pick and bar, but it breaks as 
readily in the base or binder as at the original line of demarcation. 
In fact, there is no such line. The practice is to cut out what may 
be necessary near the curb and put a new surface on the roadway 
as it stands. The result is to raise the level of the roadway at every 
resurfacing, or, if the original level at the curb be maintained by the 
method of cutting out as stated, to increase the crown of the street ; 
but as such pavements will not, as a rule, require resurfacing at 
more frequent intervals than every fifteen years, and as the surfac¬ 
ing should not raise the level more than one-half inch, the upward 
growth will not exceed 31 inches per century. 

If the surface is tarred over every year with a brush and 
sprinkled with sand, the life is lengthened. 

283. Asphalt and Coal-tar or Distillate Pavements in Washing¬ 
ton, D. C. (Extract from the Keport of Capt. E. Griffin, United 
States Engineers, Assistant to the Engineer Commissioners, for the 
year ending June 30, 1887.)—During the year 1886-1887 six per 
cent of the new pavements laid was sheet coal-tar distillate. As 
this is the first year since the organization of the present form of 
District government that coal-tar distillate pavements have been 
laid in the streets of Washington, a few words in this connection 
will not be inappropriate. Previous to 1878, 745,305 square yards 
of coal-tar pavements of various kinds were laid at prices ranging 
from $1.74 to $3.70 per square yard. Many of these pavements 
proved unreliable, either through inherent defects in the materials 
used or faulty methods of mixing and laying. Some went to pieces 
in a few years, and others deteriorated so rapidly as to soon place 
the annual cost of maintenance at excessively high figures. Of the 
so-called Evans pavement 190,663 square yards were laid, mostly in 
1873. When only two years old nearly all these pavements were 
resurfaced at an average cost of $1.09 per square yard. 

284. As late as 1877 Lieutenant Iloxie estimated twenty cents 
per yard per annum as the cost of maintaining coal-tar pavements. 

285. The average annual expenditure for maintenance of coal- 
tar pavements for the fifteen years ending June 1,1886, has been 7 T 2 g- 
cents per square yard. Of the Evans pavement, 157,324 square 
yards were resurfaced by Scharf within two years after being laid, 
and virtually became Scharf pavements. Considering them as such, 





170 


HIGHWAY CONSTRUCTION. 


the mean average annual expenditure for maintenance was 5J cents 
per square yard. For the first five years the annual average was 
3 - f \ cents; for the second five years, 6 cents; for the last five years, 
6 r 6 y cents. 

286. “ That a durable coal-tar pavement can be laid is proven 
by the fact that the 158,595 square yards of vulcanite pavements 
have only averaged 2 T 9 ff cents per square yard per annum for four¬ 
teen years* maintenance, the average being t 3 q cents per yard for 
the first five years, cents for the second five years, and 4 cents 
for the last four years. 

287. The return to the coal-tar distillate pavements was virtu¬ 
ally forced upon the commissioners by the clause in the appropria¬ 
tion act for 1886-7 which “ provided ** that under this act no 
contract shall be made for making or repairing concrete or asphalt 
pavements at a higher price than $2.00 per square yard for a quality 
equal to the best laid in the District prior to July 1, 1886, and with 
same depth of base. 

288. No bids were received for asphalt pavements in response 
to proposals advertised for under this act, so a return to distillate 
pavements was made. 

289. In 1888 bids for a modified asphalt pavement were received, 
and contracts have been made to lay a large proportion of the 
streets with it during the present year. This modified asphalt 
pavement consists of a 4-inch bituminous base, 1^ inch binder 
course, with a wearing surface of 1| inches of Trinidad asphalt 
instead of 1^ inches of coal-tar distillate composition. 

290. “ Another modification of the standard asphalt pavement 
was laid in Washington last year. This consists of a base of 4 
inches of hydraulic concrete, 1| inches of bituminous binder, and 
1^ inches of asphalt wearing surface-coat. This is in every respect 
a most excellent pavement, and more of it would be laid, only the 
contractors refuse to lay it for less than $2.10 per square yaj*i, and 
as the law prohibits the payment of more than $2.00 its use had 

'to be discontinued.*’ (Report of Capt. T. W. Symons, United States 
Engineers, Assistant to the Engineer Commissioners of the District 
of Columbia in 1889.) 

291. Specifications for Coal-tar Distillate Pavement.—Coal-tar 
distillate pavement will consist of a base and binder of 4| inches 
in depth when compacted, and a wearing surface of 14 inches in 






asphaltum and coal-tar pavements. 


171 


thickness when compacted. The space over which the pavement 
is to be laid will be excavated to the depth of 6 inches below the 
top of the surface of the pavement when completed. x4ny objec¬ 
tionable or unsuitable material below the bed must be removed and 
the spaces filled with clean gravel or sand well rammed. The bed 
will then be trimmed so as to be exactly parallel to the surface of 
the new pavement when completed, and the entire roadbed will be 
thoroughly rolled with a heavy steam roller. Upon this foundation 
will be laid the base and binder, 4^ inches in thickness, in the 
following manner: 

Base .—The base will be composed of clean broken stone that 
will pass through a 3-inch ring, well rammed and rolled with a 
steam roller to a depth of 4 inches, and thoroughly coated with 
No. 1^ coal-tar paving-cement in the proportion of about 1 gallon 
to the square yard of base. 

Binder .—The second or binder course will be composed of clean 
broken stone, thoroughly screened, not exceeding 1^ inches in the 
largest dimension, and No. 4 coal-tar paving-cement. The stone 
will be heated to a temperature between 230 and 250 degrees Fahr., 
by passing through revolving heaters and thoroughly mixed by 
machinery, with the paving-cement in about the proportion of 1 
gallon of No. 4 tar to 1 cubic foot of stone. It will be hauled upon the 
work, spread upon the base course at least 2 inches thick, and im¬ 
mediately rammed and rolled with hand and steam rollers while in 
a hot plastic condition. 

Wearing Surface .—The wearing surface will be composed of the 
following materials in the given proportions: 


Per cent. 

Clean sharp sand.63 to 58 

Broken stone or rock-dust.28 to 23 

Paving-cement...13 to 15 

Hydraulic cement. 0.9 

Slaked lime. 0.15 

Flour of sulphur. 0.1 


The sand shall be clean, sharp river sand, free from clay, and 
of such size that not more than 20 per cent shall be retained upon 
a sieve of twenty meshes to the inch and not more than five per 
cent shall pass through a sieve of 70 meshes to the inch, about 60 
per cent to be coarser than 40 meshes to the inch. The broken 











172 


HIGHWAY CONSTRUCTION. 


stone or stone-dust shall be the residue from the crushing of stone 
from the base and binder which passes a sieve of not more than 6 
meshes to the inch. 

The paving-cement shall be composed of fine Trinidad asphalt, 
twenty-five to thirty parts; No. 4 coal-tar paving-cement, seventy- 
five to seventy parts. The refined asphalt must contain at least 60 
per cent of pure bituminous matter, soluble in carbon bisulphide. 
The No. 4 coal-tar paving-cement must correspond to a standard to 
be furnished by the engineer, and be free from excess of sooty mat¬ 
ter, naphthaline and creosote oils. The hydraulic cement, lime, and 
sulphur must be of the best commercial quality. 

The materials for the wearing surface will be heated to not over 
26 degrees Fahr., the paving-cement in kettles, the sand and stone- 
dust in revolving heaters. To the latter the hydraulic cement, lime, 
and sulphur will be added cold in the sand-box before going to the 
mixer. They will be thoroughly mixed by approved machinery, 
and the mixture carried upon the work, where it will be spread upon 
the binder course 2 inches thick with hot iron rakes and other 
suitable appliances, and immediately compacted with hot tamping- 
irons and hand and steam rollers, while in a hot and plastic state. ‘ 
In spreading the material the joints are to be diagonal to the line 
of the street. The surface will be finished with a dusting of dry 
hydraulic cement rolled in. In cool weather or when ordered the 
carts carrying the mixture are to be protected with canvas covers. 

The pavement so constructed must be a solid mass 6 inches 
thick, and must be thoroughly rolled and cross-rolled until it has 
become hard and solid. The relative proportions of the component 
materials will be changed upon the order of the engineer, as occa¬ 
sion shall require. 

All materials, as well as the plant and methods of manufacture, 
will be subject to the inspection and approval of the engineer. 

The degree of fineness, both of sand, stone-dust, and powdered 
limestone, will be determined by testing with screens as follows: 
The powdered carbonate of lime will be of such degree of fineness 
that 16 per cent of weight shall be an impalpable powder of limestone, 
and the whole of it shall pass a No. 26 screen. The sand will be 
of such size that no more than 50 per cent of it will pass a No. 80 
screen, and the whole of it shall pass a No. 20 screen. The broken 
stone or stone-dust shall be the residue from the crushing of stone 






ASPHALTUM AND COAL-TAR PAVEMENTS. 


173 


from the base and binder which passes a sieve of not more than 6 
meshes to the inch. 

Gutters, wherever directed, will be granite-block or brick, of such 
width as may be directed, laid upon a hydraulic base of not less than 
4 inches in thickness, in accordance with the specifications for 
granite-block pavement or brick gutters. 

292. Asphalt Block Pavements.—The manufacture of paving- 
blocks from crushed stone and asphaltic cement was begun in San 
Francisco in 18l>9, but, in consequence of imperfectly prepared 
materials and crude appliances, the blocks were weak and friable 
and the results were unsatisfactory ; since that time to the present 
improvements have been made in the processes and machinery, 
resulting in the production of a tougher and more enduring block, 
a large amount of which has been laid, particularly in Washington 
and Baltimore. 

Composition .—The blocks are composed of crushed stone and 
asphaltic cement in the proportion of 87 to 90 per cent of stone 
and 13 to 10 per cent of cement. 

The stone employed is trap, gneiss, limestone, etc.; the stone is 
broken and partially pulverized under crushers and rollers ; the 
asphaltic cement is prepared from any selected asphaltum (usually 
Trinidad and California) in the manner described in Art. 96. 

The composition of the blocks now used in Washington, 


D. C., is: 


13 per cent. 


Asphaltic cement, 
Limestone-dust . 
Crushed gneiss. . . 



100 per cent. 


(Sand is not used,because it has been found to cut the moulds.) 

Manufacture .— The materials are heated to a temperature of 
300° F., then thoroughly combined in mechanical mixers. As the 
mixture leaves the mixing apparatus it passes into a pressing 
machine very similar to that used for pressing bricks, and is 
moulded and compressed while hot into blocks measuring 
4 X 5 X 12 inches; the blocks are then cooled under water and are 
readv for use. The blocks weigh from twenty-two and a half to 
twenty-four pounds each, according to the specific gravity of the 








I 


174 HIGHWAY CONSTRUCTION. 

stone employed, and about twenty-six blocks are required per 
square yard. The dimensions of blocks from different factories 
vary slightly. 

The blocks are laid on the street in close contact, in the same 
manner as stone paving-blocks, either with or without an artificial 
foundation; the foundation usually employed is gravel or gravel and 
sand or sand alone. 

293. Advantages and Defects.—The advantages and defects 
stated under Asphalt Pavement in Articles 221 and 222 are equally 
applicable to asphalt block pavements. The special advantage 
which they possess over “ Sheet ” asphalt is that they can be made 
at a factory located near the materials, whence they can be trans¬ 
ported to the place where they are to be used, and laid by ordinary 
pavers without the aid of skilled labor ; whereas sheet pavements 
require special machinery and skilled labor in each city where they 
are laid. 

Compared with stone blocks they are much smoother and less 
noisy, and they form a practically impervious pavement, because 
under the action of the sun and traffic the asphalt cements the 
blocks together. 

For narrow well-travelled streets they do not make a suitable 
pavement, but where the traffic is of such a character (such as resi¬ 
dence streets where the traffic is light) to warrant their use they 
make when laid upon a concrete foundation an excellent pavement, 
smooth, durable, and easily cleaned, healthy and pleasant to the 
eye. 

294. Cost.—The blocks cost abouc 160.00 per 1000 or $1.56 per 
square yard f. o. b. at the factory. 

The cost of construction will vary with the locality, cost of 
transportation, character of foundation, etc. Table XXXVI shows 
the extent and cost of construction in some of the principal cities in 
1890. 




ASPHALTUM AND COAL-TAR PAVEMENTS. 


175 


TABLE XXXVI. 

Extent and Cost of Asphalt-block Pavements in some of the 
Principal Cities of the United States in 1890. 


Cities. 

Extent. 

Miles. 

Cost of Construction 
per square yard. 

Philadelphia, Pa. 

18.80 


Washington, D. C. 

10.10 

$2.00 

Camden, N. J. 

5.86 

2.00 

Chicago, Ill. 

4.11 

2.00 

Trenton, N. J. 

2.50 

2.50 

Schenectady, N. Y. 

0.75 



295. Cost of Maintenance.—No statistics are available as to the 
cost of maintenance. Some of the cities using them report that no 
repairs have been made in five years, and that, as the traffic is very 
light, it does not appear likely that repairs will have to be made; 
others report that no repairs have been made and that the blocks 
are badly worn. (See also Art. 782, et seq.) 

296. Specifications for Laying Compressed-asphalt Blocks.— 
Upon the soil-bed, previously compacted by rolling and ramming, 
a layer of bank gravel, screened from all pebbles measuring more 
than one and one-half (1|) inches in their largest dimensions, will 
be laid of such depth as to give five (5) inches in thickness when 
compacted by rolling and ramming. Upon the gravel will be 
spread a layer of fine sharp sand two (2) inches in thickness, to 
serve as a bed for the blocks, which will be laid directly upon and 
embedded in it with close joints. Special care will be observed to 
make the surface of the sand exactly parallel to the surface of the 
pavement when completed. The blocks shall be laid by the 
pavers standing or kneeling upon the blocks already laid, and not 
upon the bed of sand. 

The blocks shall be laid with their length at right angles to the 
axis of the street; each course will be formed with blocks of a uni¬ 
form width and depth. The blocks shall be so laid that all longi¬ 
tudinal joints shall be broken by a lap of at least four (4) inches. 
Each course of blocks will be driven against the course preceding 
it by a heavy wooden maul, in order to make the lateral joints as 
tight as possible. The longitudinal joints will be closed by pressing 
on a lever inserted at the end of the course adjoining the curb, and 





















176 


HIGHWAY CONSTRUCTION. 


keying with a block cut to the required size. When laid, the 
blocks will be immediately covered with clean, fine sand entirely 
free from loam or earthy matter, perfectly dry, and screened 
through a screen having 20 meshes to the inch. The blocks will 
then be rammed by placing an iron plate, 24 inches by 8 inches, 
and f inch thick, over four blocks, and striking on the plate with a 
rammer weighing not less than 45 lbs. The ramming will be con¬ 
tinued until the blocks reach a firm, unyielding bed and present a 
uniform surface, with the required grade and crown. Any lack of 
uniformity in the surface must be corrected by taking up the 
blocks, increasing the sand bedding, and relaying them. When the 
ramming is completed, a sufficient amount of fine, dry sand, as 
above described, will be spread over the surface and swept into the 
joints. 

297. American Bituminous-rock Pavements.—Beds of sand¬ 
stone rock impregnated with bitumen are found in many places 
in the XJ nited States, but it is only within the last few years 
that it has come into use as a paving material. San Francisco, 
Los Angeles, and other cities now have several miles of this pave¬ 
ment. 

298. The rock is quarried, broken into fragments, heated, and 
while hot taken to the street and comj)ressed by rolling and 
tamping. 

299. The reports concerning the durability of these pavements 
is conflicting. A claim is made that pavements made of this 
material 15 years ago and used under heavy traffic have recently 
been removed and found to have lost very little either in weight 
or thickness. On the other hand, it is claimed that these pave¬ 
ments are soft; that wheels and horses sink into them quite 
deeply, but these marks appear to be more or less obliterated by 
the next passing vehicle. 

The granular nature of these pavements renders them less 
slippery than the ordinary asphalt pavements. They also possess 
the quality of resisting disintegration by moisture. It is also 
claimed that these pavements stand equally well the high tem¬ 
perature of the interior cities and the cold, damp atmosphere of 
the coast. 

300. Cost of Construction.—The cost of construction in the 
West is less than that of the standard asphalt, the average be.ng 



ASPHALTUM AND COAL-TAR PAVEMENTS. 


177 


about $2.50 per square yard, including a 6-inch concrete base, In 
he Eastern cities there is but little difference in their cost. 

301. Cost of Maintenance.—As none of these pavements has been 
laid on a large scale for a sufficient length of time, nothing can be 
said as to the cost of maintaining them. 

302. One ton of the bituminous rock will form 10 square yards 
of pavement 2 inches thick. 

303. Specifications for Bituminous-rock Pavements.—The man¬ 
ner of laying the bituminous rock is left to the contractor, except 
in the following particulars: 

The bituminous rock used for the paving must contain not less 
than 7 nor more than 13 per cent of its weight of bitumen. 

The powdered rock shall be prepared at a uniform temperature 
in suitable boilers. 

Ten days before the award of contracts bidders must deposit in 
the office of the engineer samples of the bituminous rock which 
they propose to use. Each sample shall bear the bidder’s name 
and the name of the place where obtained. All materials used 
must conform to the samples so deposited. If other material is 
wished to be used, samples of them must be deposited and accepted 
by the engineer. 

The asphalt covering, when completed, is to have a thickness 
of at least 2 inches, everywhere equally firm and compact, and 
jointing densely to the curb of the sidewalks, gutter-covers, etc., 
and the surface must in every place conform to the prescribed 
longitudinal transverse profiles. 

Laying the Asphalt .—The asphalt is to be laid in dry weather 
Work must not be carried on during rains or snowstorms. Only 
on the special permission of the engineer may the asphalt be laid 
on the concrete, which is to be thoroughly cleaned of earth, dirt, 
and loose substances of all kinds. If the cleaning reveals any soft 
or injured places in the concrete, they are to be chiselled out and 
filled with new concrete containing a greater proportion of cement. 
This is not to be covered over until it has set. 

All possible measures must be taken to prevent the cooling 
of the asphalt powder while being carried to the place where it is 
to be laid. While the hot powder is being spread out and before 
the commencement of the tamping and rolling, the greatest care 
must be exercised in removing all, even the smallest, foreign 




178 


HIGHWAY CONSTRUCTION. 


bodies, such as stones, paper, wood, straw, leaves, cigar-stumps, 
etc., and no one shall be allowed to throw such bodies on the 
work. Moreover, the carts in which the asphalt is to be moved 
must be carefully cleaned after each use. The engineer lias the 
right to require proofs of their cleanliness, and to require a second 
cleaning under supervision. 



CHAPTER VI. 


BRICK PAVEMENTS. 

304. Brick, although one of the oldest materials used for 
paving, was not employed for this purpose in the United States 
until about twenty years ago. The first brick pavement laid in the 
United States was in Charleston, W. Va., in 1872. Since then the 
nse of brick as a paving material has extended over a wide section 
of country; and in localities with moderate traffic such pavements 
appear to give satisfaction. 

305. The advantages of brick pavements may be stated as fol¬ 
lows: 

(1) Ease of traction. 

(2) Good foothold for horses. 

(3) Not disagreeably noisy. 

(4) Yields but little dust and mud. 

(5) Adapted to all grades. 

(6) Easily repaired. 

(7) Easily cleaned. 

(8) But slightly absorbent. 

(9) Pleasing to the eye. 

(10) Expeditiously laid. 

(11) Durable under moderate traffic. 

Brick pavements will be found in many localities to be superior 
to wood or broken stone, and in many cities and towns will be 
found superior to stone blocks. 

306. The Defects of Brick Pavements.—The principal defects of 
brick pavements arise from lack of uniformity in the quality of the 
bricks and the liability of incorporating in the pavement bricks of 
too soft or porous structure, which crumble under the action of 
traffic or frost. 

The employment of unsuitable brick is liable to be fostered by 
a popular desire to help a local industry without due regard to the 

179 


180 


HIGHWAY CONSTRUCTION. 


TYPES OF BRICK PAVEMENTS. 




Fig. 17.—Plan of Hale Pavement. 





Fig. 18— Section of Brick Pavement on Concrete. 



Fig. 1 9.—Plan showing Arrangement of Junction. 



































































































BRICK PAVEMENTS. 


181 


-quality of the local clays for the manufacture of good paving brick. 
This circumstance, together with the comparative ease with which 
contractors who have little experience can bid on this class of work, 
and the difficulty of rejecting the lowest bid by local authorities, 
will in many places result in the failure of the brick pavements. 
If cities, however, in making contracts for brick pavements, will 
keep these contingencies in mind, and as far as possible exercise 
discrimination in selecting bricks made especially for this purpose 
and contractors interested in making these pavements popular, 
then the development of a great industry may be anticipated. 

307 . Durability.—Brick has been used for upwards of a hun¬ 
dred years in the Xetlierlands, and pavements laid half a century 
ago are still in good condition. There are several brick pavements 
in the United States from ten to eighteen years old which are 
still in good condition. 

308 . The general experience with pavements formed of suitable 
brick, laid on an unyielding foundation, with the joints filled with 
bituminous or Portland-cement grout, is that they furnish a smooth 
and durable surface, well adapted to moderate traffic. 

309 . Failures of the earlier pavements are frequently reported. 
These pavements were generally constructed on defective founda¬ 
tions, and with the ordinary building bricks of the locality. Such 
failures are the result of overhaste in the selection of the material, 
and poor foundations. 

310 . The durability of the bricks seems to depend (1) on the 
clay from which they are made being practically free from lime; 
(2) on the thorough grinding and mixing of the clay, so as to have 
no lumps in the bricks; (3) upon the bricks being thoroughly an¬ 
nealed. 

311 . The brick pavements at The Hague, Holland, are made of 
n hard-burned brick 8.668 inches by 4.33 inches wide and 2.16 
inches thick. They are laid on a sand foundation 7.88 inches deep, 
with very little clay. Joints are laid as close as possible. 

The Hague is a city of residences, and street traffic is very light. 
Amsterdam is paved almost entirely with brick. The road from 
Utrecht to Connighem, twenty-seven miles, is paved with brick. 

312 . Bricks are successfully used in Rotterdam, which is a com¬ 
mercial city. Two classes of brick are used—one made from local 
clays, and the other a scoria brick, manufactured by the Tees Scoria 



182 


HIGHWAY CONSTRUCTION. 


Brick Company, of England. The local bricks are preferred for 
light traffic, and for medium traffic the scoria bricks. 

313. Size and Shape of Bricks.—Bricks are passing through an 
ordeal similar to that through which wood for paying passed many 
years ago, with practically the same results, viz., that with a proper 
foundation neither odd shapes, grooves, lugs, nor other devices are 
necessary or beneficial. Experience shows that the most economi¬ 
cal and desirable size for paving bricks is that of the standard 
building brick. Bricks of this size can be made more cheaply, 
burned more uniformly, and those which are unsuitable for paving 
can be utilized for building purposes, which would be impracticable 
with odd shapes. The imperfect ones of said shapes or peculiar 
form are so much waste material, and the cost of their manufacture 
must be added to the price of the good ones in order to protect the 
manufacturer from loss. Moreover, with irregular sizes and odd 
shapes it would be necessary for the towns employing brick pave¬ 
ments to keep a large stock of the different bricks on hand to make 
rejoairs, which would be expensive and troublesome 

314. duality of Bricks.—The qualities essential to a good 
paving brick are the same as for any other paving material, viz., 
hardness, toughness, and ability to resist the disintegrating effects 
of water and frost. As with other materials, porous brick are unfit 
for paving. 

These qualities are not obtained, as is commonly supposed, by 
vitrifying the bricks: in fact the application of the term vitrified to 
paving bricks is a misnomer. The process of vitrification is to con¬ 
vert into glass by fusion or the action of heat. Glass is a smooth, 
impermeable, brittle substance, easily fractured; therefore the edges 
of bricks that are vitrified or turned into glass will be quickly 
broken off, and their surface will be slippery. Vitrification adds 
nothing to the strength; in fact it defeats the object for which the 
bricks are made. 

315. The required qualities are imparted to the brick by a pro¬ 
cess of annealing. The bricks should be burned just to the point 
of fusion, then the heat gradually reduced until the kiln is cold. 
This process will produce a brick thoroughly compact, hard, and 
tough. If the cooling off is done quickly, it will produce a brittle 
brick, that will speedily go to pieces under traffic. 

316. Foundation.—A solid unyielding foundation is as indis- 



BRICK PAVEMENTS. 


183 


pensable with bricks as with any other paving material: the failure 
of the earlier pavements was due, in many cases, more to defective 
foundations than to defective material. The use of plank laid on 
sand is objectionable for the same reasons stated under wood pave¬ 
ments, Articles 185, 186. 

317 . The foundation in all cases should be formed of cement 
concrete, the aggregate of which, in localities where stone or gravel 
are unobtainable, may be of broken bricks. 

318 . Manner of Laying.—The bricks should be laid on edge, as 
closely and compactly as possible, in straight courses across the 
street, with the length of the bricks at right angles to the axis of 
the street. Joints should be broken by at least 3 inches. None 
but whole bricks should be used except in starting a course or 
making a closure. Before the closure is made, each single course 
should be pressed as compactly together as possible with an iron 
bar applied to the curb end of the row, and then keyed in place 
with a close-fitting brick. After 25 or 30 feet of the pavement is 
laid, every part of it should be rammed with a rammer weighing 
not less than 50 pounds, and the bricks which sink below the gen¬ 
eral level should be removed and replaced by a brick of greater 
depth. After the ramming and rectification Portland-cement grout 
should be poured into the joints until it appears on the surface ; 
then the whole surface should be covered with a layer of dry sand 
\ inch deep. 

319 . At street intersections the course should be laid meeting 
at an angle, as shown in Fig. 19, so that the courses may not run 
parallel to the traffic. 

320 . Cost of Brick Pavements.—The cost of construction of 
these pavements depends largely upon the facilities for obtaining 
the requisite material and the character of the foundation. 

The cost of a first-class brick pavement per square yard may be 
estimated as follows: 

Excavation..... $. 

|Th of a cubic yard of concrete. 

T yth “ “ “ “ sand... 

72 bricks of standard size... . 

Labor laying, etc. 

Freight. 

21 gallons of asphaltic cement. 


Total 






















184 


HIGHWAY CONSTRUCTION. 


321. Table XXXVII shows the cost in various localities in 
the United States. 


TABLE XXXVII. 


Extent and Cost of Brick Pavements in several Localities in 

the United States in 1890. 


Cities. 

Extent. 

Miles. 

Cost of Construction 
per square yard. 

Columbus, Ohio. 

21.00 

$1.75 to $2.35 

Philadelphia, Pa. 

19.80 

2.05 

Decatur, Ill. 

10.00 


Bloomington, Ill. 

6.00 

1.62 

Toledo, Ohio. 

4.70 

2.10 

Omaha, Neb. 

3.00 

1.75 to 2.14 

Parkersburg, W. Va. 

2.20 

1.09 to 1.40 

Quincy, Ill. 

2.00 . 

1.80 

Springfield, Ill. 

1.50 

1.50 

Bucyrus, Ohio. 

1.25 

2.30 

Rochester, New York. 

1.25 

2.25* 

Trenton, N. J. 

1.00 

2.00 

Nashville, Teun.. 

0.75 

1.35 

Detroit, Mich. 

0.61 

2.80 

Chicago, Ill. 

0.38 

2.00 

St. Paul, Minn. 

0.34 

2.00 

Cumberland, Md. 

0.33 

1 25 

Wheeling, W. Va. 

10.00 

1.00 to '1.41 


* Concrete foundation. 


322. Variety of Systems. —Many patented systems of forming 
brick pavements have been introduced, differing either in the shape 
and size of the bricks or in the method of laying them. The fol¬ 
lowing are representative systems: 

The Hayden Paving-block (Fig. 19c).—The shape and manner 
of laying these blocks is patented. The blocks are square in plan, 
with deep hollows underneath to facilitate burning and save mate¬ 
rial; the top surface is flat, broken by indentations, and the edges 
of the top are bevelled. The blocks are made in two sizes, the 
smaller ones 5£ inches deep and 5f inches square. 

The manner of laying these blocks is as follows: The surface of 
the street, being brought to the required grade, is covered with 8 
inches of broken stone, which is compacted by rolling or ramming; 
on the broken stone a layer of 2 or 3 inches of sand is spread, on 
which the blocks are laid. The hollows in the bottom of the 






























BRICK PAVEMENTS 


185 


blocks are filled with moist sand, then laid in position, rammed to 
grade, and the joints filled with hot pitch. 



Fig. 1 9a. 


The cost of this pavement is about 11.92 per square yard. 

The clay from which these blocks are made is composed of 

Silica.... 

Alumina. 

Iron. 

Lime.... 

Magnesia 

Alkalies. 

Water... 

100.00 per cent 

323. The Halwood Block— These blocks are composed of a 
mixture of mica shale, clay, and sand. The blocks measure 
3x4x9 inches, taking 48 to a square yard. They are laid on a 
foundation of either 6 inches of concrete or 8 inches of broken 
stone, joints filled with coal-tar. The cost per square yard, includ¬ 
ing foundation, is from $2.50 to $2.10. 


76.24 per cent 
16.87 
.16 
.50 
trace 
1.09 
5.14 








































































































































































































186 


HIGHWAY CONSTRUCTION. 


324. The McReynolds Patent Brick. —The patent consists in 
the bricks having lugs, and in one end of each brick a recess. The 
claim is that this arrangement permits the joint-filling to flow 
around the brick, and that these projections act as an obstruction 
to the cement running during hot weather to the gutter. 

325. The Hale Pavement. —Introduced in 1873 is a patent pro¬ 
cess foi laying any brick for paving purposes, the novelty being in 
the foundation, which consists of 3 inches of sand, on which are 
laid 1-inch oak boards dipped in coal-tar. The boards are laid either 
lengthwise or crosswise of the street. On the boards a layer of clean 
sand from an inch to an inch and a half thick spread, and the bricks 
laid on edge, “ herring-bone” fashion, with the joints filled with tar 
or sand as may be desired. This costs in West Virginia $1.35 per 
square yard, varying of course with the cost of the brick used. A 
royalty of 10 cents per square yard is charged by the Hale Com- 
for the use of this method (see Figs. 16 and 17). 

326. “ Charleston Plan.” —On the graded surface of the street 
spread 3 inches of clean coarse sand; on this place 1-inch oak 
boards dipped in hot coal-tar; on the boards spread a cushion-coat 
of clean sand 1^- inches deep; on this lay the bricks (common red) 
on edge, “ Herring-bone” fashion; cover the bricks with dry clean 
sand, and broom well to fill the joints. 

327. “ Wheeling Plan/' —The roadbed is first graded and com¬ 
pacted by rolling with a 5-ton roller, then 3 to 7 inches of coarse 
gravel and sand is spread and rolled; on this the bricks are laid 
with their length at right angles to the axis of the street and then 
brought to a solid bearing by rolling; the joints are filled with 
sand and coal-tar, and the surface covered with dry sand. Both 
the common red and special bricks are used. 

328. Paving-bricks are made at Kakos near Buda Pesth from 
carefully selected clay mixed with a little lime. The bricks when 
moulded are subjected to a pressure of about 3500 pounds per 
square inch, and then burned nearly to vitrification. The product 
is regular in form, homogeneous, of uniform density, and of great 
resistance to wear. According to the experiments of Prof. Ignsez, 
they have supported without deformation or Assuring a maximum 
load of over 45,000 pounds per square inch and a mean load of 
31,426 pounds per square inch. A square meter (1196 square yards) 
of this pavement costs $3.80. In forming the paving, the soi) is 



BRICK PAVEMENTS. 


187 


first consolidated and a bed of ordinary brick masonry is laid upon 
it; the paving-bricks are set in mortar, leaving a joint of T 4 (j- of an 
inch between them to be filled with cement. The dimensions of 
the bricks are 7.87 X 7.87 X 3.9 inches and they weigh 24 pounds 
each. It takes 22 bricks to lay 1 square yard of paving. The brick 
foundation is 6 inches deep. The pavement made with these bricks 
is easy to clean, does not become slippery, and is pleasant to drive 
over. The only objection is that it is somewhat noisy in the nar¬ 
row streets. 

329. Iron Bricks, so called, are said to be used satisfactorilv 
for paving in Germany. These bricks are made by mixing equal 
parts of finely ground red argillaceous slate and finely ground clay, 
with the addition of 95 per cent iron-ore. The ingredients thus 
mixed together are then moistened with a solution of 25 per cent of 
sulphate of iron to which fine iron-ore is added; after this the com¬ 
pound is shaped in a press, dried, dipped once more in a concen¬ 
trated solution of finely ground iron-ore, and then baked in an oven, 
for about 48 hours in a reducing-flame. 

330. Bricks made from blast-furnace slag and scoria have been 
tried; they are durable, but soon wear slippery and afford little foot¬ 
hold for horses. Ordinary building-bricks saturated with gas-tar 
have been experimented with in Nashville, Tenn. The results were 
not satisfactorjq and the pieces of experimental paving have been 
removed. 

331. Heads of Specifications for Brick Pavement. 

(1) Preparation of roadbed. 

(2) Foundation. (Concrete.) 

(3) Quality of the Bricks .—The bricks shall be manufactured 
from suitable clay containing not more than one per centum of 
lime. 

They must be burned especially for paving purposes. They 
shall have a resistance to crushing of not less than 8000 pounds, per 
square inch on the flat, and must not absorb more than -gfo of 
their weight of water after 48 hours' immersion. They must possess 
such a degree of toughness that when struck a quick blow with a 
4-lb. hand hammer on the edges, the edges shall not spall or chip. 

( 4 ) & tize and Shape. —They shall be of a uniform size of 8 x 4 X 2£ 
inches, shall be square on the edges, straight, and free from fire- 
cracks or checks; when broken, the fracture shall be smooth and 




188 


HIGHWAY CONSTRUCTION. 


straight, not conchoidal; and the texture shall he uniform through¬ 
out and not granular. 

(5) Samples .—Not less than three bricks of the quality, size, 
and shape proposed to be used shall be furnished with each pro¬ 
posal, each brick to be labelled with both the bidder’s and maker's 
name and address; these samples shall be deposited in the office of 

three days before the time of opening the bids. They 
will be subjected to the required tests, and the characteristics of 
those deposited by the successful bidder will become the standard 
by which will be tested all the bricks to be furnished by him, and 
no deviation from this standard greater than one per cent in any 
particular will be permitted in the bricks placed in the work. 

(6) Inspection and Culling .—The bricks will be inspected after 

they are brought upon the ground, and all bricks which are soft, 
cracked, checked, overburned, or otherwise defective in quality or 
dimensions will be rejected and must be immediately removed 
from the line of the work. The contractor must furnish such 
laborers as may be necessary to aid the inspector in the examination 
and the culling of the bricks; and in case the contractor neglect or 
refuse to furnish said laborers, such laborers as in the opinion of 
the may be necessary will be employed by said 

, and the exjiense thus incurred by will be de¬ 

ducted and paid out of any money then due or which may there¬ 
after become due to said contractor under the contract to which 
these specifications refer. 

(7) Cushion-coat .—On the concrete foundation a layer of clean 
sharp sand, free from moisture, will be evenly spread to a depth of 
^ inch. The sand if not dry must be made so by the application of 
artificial heat, in such apparatus as may be suitable for the purpose 
and approved of by the engineer. 

(8) Laying the Bricks .—The bricks Shall be set on the cushion- 
coat in close contact with each other, both on sides and ends; they 
will be laid in parallel courses across the street, with the length of 
the bricks at right angles to the axis of the street. The bricks of 
adjoining courses shall break joints by at least 3 inches. At street- 
intersections the bricks will be laid on the diagonal, as shown on 
the plans. . . . Whole bricks only shall be used, except in starting 
a course or making a closure and in paving around manhole-heads, 
etc. 



BRICK PAVEMENTS. 


189 


(9) Ramming. —The bricks shall he rammed to a solid bearing, 
with hand rammers weighing not less than 50 pounds, and all 
bricks which sink below the general level must be removed and the 
sand bedding increased until the level is uniform. 

(10) Jointing. —After the bricks have been rammed to an un¬ 
yielding bearing the joints will be filled full with grout made of 
equal parts of hydraulic cement and sand. 

(11) Interpretation of specifications. 

(12) Omissions in specifications. 

(13) Engineer defined. 

(14) Contractor defined. 

(15) Notice to contractors, how served. 

(16) Preservation of engineer’s marks, etc. 

(17) Dismissal of incompetent persons. 

(18) Quality of materials. 

(19) Samples. 

(20) Inspectors. 

(21) Defective work, responsibility for. 

(22) Measurements. 

(23) Partial payments. 

(24) Commencement of work. 

(25) Time of completion. 

(26) Forfeiture of contract. 

(27) Damages for non-completion. 

(28) Evidence of the payment of claims. 

(29) Protection of persons and property. 

(30) Indemnification for patent claims. 

(31) Indemnity bond. 

(32) Bond for faithful performance of work. 

(33) Power to suspend work. 

(34) Right to construct sewers, etc. 

(35) Loss and damage. 

(36) Old materials, disposal of. 

(37) Cleaning up. 

(38) Personal attention of contractor. 

(39) Payment of workmen. 

(40) Prices. 

(41) Security retained for repairs. 

(42) Payment, when made. 4 inal acceptance. 



190 


HIGHWAY CONSTRUCTION. 


332. Specifications for Brick Pavements in Memphis, Tenn.—The 

roadway between curb lines shall be taken down to sub-grade, care 
being taken not to plough within three inches (3) of the sub-grade 
stakes, which last shall be carefully removed with jnck and shovel, 
in such manner as to leave a true and perfect surface, which shall 
be rolled down with a 5-ton roller three times before the concrete 
foundation is laid. Before the sub-grade foundation is finally 
fixed, all water and gas pipes must be put in and adjusted; water- 
pipes must be of lead, double strength, and the gas of the best gal¬ 
vanized pipe; the trenches shall be filled in layers of three inches, 
and carefully rammed to within six inches of sub-grade and the 
balance of trench concreted. 

Concrete .—Upon the sub-grade thus formed shall be spread 
the concrete foundation, composed of hard limestone, broken or 
crushed to pass a two-inch ring,—the same to be free of all dirt, 
trash, etc.,—clean, sharp sand mixed with fine gravel, and the best 
fresh Louisville cement, in the following proportions, viz., one 
measure of cement and two of sand, thoroughly mixed, and then 
made into mortar, with the least possible amount of water; 
into this will be put the macadam, which shall first be well wet, 
and the whole worked into a concrete in such quantities as will 
produce a surplus of free mortar when well rammed. This pro¬ 
portion, when ascertained, will be regulated by measure. Each 
total of concrete will be thoroughly mixed, in suitable boxes, with 
hoes and shovels, the mortar always to be mixed fresh before being 
applied to the broken stone. It will then be spread and at once 
thoroughly compacted by ramming with heavy cast-iron rammers, 
until free mortar appears on the surface: the whole operation 
shall be done as expeditiously as possible. The upper surface will 
be made exactly parallel with the surface of the pavement to be 
laid, by floating over the surface with cement and the straight 
edge. The depth of concrete consolidated shall not be less than 
nine (9) inches. No walking or driving shall be permitted on the 
concrete when it is setting, and it shall be allowed to set for three 
(3) days before any pavement is laid on it. 

Pavement— On the concrete foundation thus prepared a bed 
of clean, sharp sand, free from moisture, two (2) inches deep, shall 
be laid. The paving bricks to be used shall be such as shall be 
satislactoiy and acceptable to the Engineer, and shall conform 



BRICK PAVEMENT'S. 


191 


strictly to the samples offered by the contractor, and accepted by 
the Engineer and the Council. The sand must be brought to a 
true and perfect surface, and made to conform strictly to the grade 
pegs set by the Engineer, by means of a drag straight-edge, seven 
(7) feet long, drawn over the surface, and resting on two pieces of 
scantling 2x1x16 feet long, having planed surfaces, the top of 
the sand bed being flush with the grade pegs. Upon this bed of 
sand the paving bricks are to be laid on edge, at right angles to 
the line of curbs, in parallel lines, in as close contact as possible on 
sides and ends; the joints broken one with another, by starting at 
curb-lines with half-bricks, in alternate rows, so as to break the 
joints. No half or broken brick shall he laid except at the curb¬ 
lines, in order to make closures, but the brick must be laid whole 
throughout, except as above named. 

As the pavement is laid over thirty or more feet at a time, it 
shall be thoroughly rammed over three times with a flat iron ram¬ 
mer, about one foot in diameter, weighing thirty or forty pounds, 
which must be done by lifting and dropping the rammer verti¬ 
cally. When the bricks have been rammed to a solid bearing and 
brought to a perfect surface, the interstices shall then be thor¬ 
oughly and completely filled, from bottom to top, with distilled 
coal-tar pitch (known as No. 6) heated up to 300 degrees. All 
crevices must be filled, and the entire top surface covered to a 
depth of not less than one fourth inch, and upon this must be 
spread one fourth inch of clean, sharp sand, which must be com¬ 
paratively dry and free from moisture. This sand must be thrown 
evenly over the boiling pitch as rapidly as the pavement is filled 
in, and the pitch spread over the surface of pavement, the aim and 
object being to make the pavement one solid mass, which, when 
completed, shall be practically a fixture and Avater-tight. The 
bricks shall be rigidly inspected before being laid in the pavement, 
and all objectionable ones removed. The sand and pitch shall be 
acceptable, and shall also be applied as directed by the Engineer, or 
his assistant, and to his entire satisfaction and acceptance. The 
pavement, when completed, must be smooth, and conform to the 
grades given by the Engineer. 

Dimensions of Brick. —Square-edged, to wit: Length, 8f 
inches; thickness, 2f inches; width, 4 inches. Halwood block, 
patent length, 9 inches; width, 4 inches; thickness, 3 inches. 





192 


HIGHWAY CONSTRUCTION-. 


Bricks thoroughly burned throughout to vitrification. 

333. Extracts from Specifications for Laying Brick Pavements 
in the City of Bloomington, Ill. 

Roadbed .—The roadbed shall be carefully graded and shaped 
to an elevation of at least eleven inches below the established grade 
line given by the City Engineer, and intended for the surface of 
the pavement when completed. The City Engineer, or his assist¬ 
ant, shall set all grade stakes, and thereafter the same must be 
protected and maintained by the contractor and his employees un¬ 
til the services of the same are no longer needed. The contractor 
shall do all necessary grading and shall provide all earth necessary 
for filling, and dispose of all surplus excavation by removing the 
same to the lawns or other dirt streets as the City Engineer may 
direct. In order to bring the roadbed to the proper shape and 
grade, a pattern made under the direction of the City Engineer, 
giving the street proper convexity, shall be continuously used as a 
guide to the graders. After said roadbed is properly graded and 
shaped it shall be thoroughly rolled and compacted by the steam 
roller, wherever it is practicable to use said roller; and wherever the 
use of the steam roller is impracticable the foundation shall be com¬ 
pacted either by the use of the smaller roller or by tamping. The 
roadbed, being properly rolled, shall then be covered with cinders 
of a uniform depth of at least three inches, and the same shall be 
rolled and compacted as before; and there shall then be spread a 
covering of sand of sufficient thickness to grade the surface of said 
roadbed to a uniform shape, regular and smooth surface for receiv¬ 
ing the bottom course of brick. Should any depressions appear 
during the process of rolling, such as the settlement of sewer 
branches or otherwise, the same must at once be filled up and 
again rolled, so that, when the process of rolling shall cease, the 
entire roadbed shall be uniform and complete in its settlement. 

Brick Work .—There shall then be placed a course of brick 
upon their flat surface, long dimensions parallel with the street, 
laid as closely together as practicable and all joints broken. Dry 
sand, screened, will then be spread over the entire course of brick, 
and well brushed in so as to completely fill all crevices. Sufficient 
screened sand will then be placed on the bottom course of brick to 
make a bed of one inch depth upon which to place the top course 
of brick. The top course of brick will then be laid on their longest 





BRICK PAVEMENTS. 


193 


two-inch surface across the street, breaking joints and laying the 
brick as closely together as possible. Nothing less than whole bricks 
to be used in the top course except were necessary to break joints. 
The courses of brick in the top course must be kept straight across 
the street, at right angles to the curbing as near as practicable. Brick 
that are badly swelled and irregular will not be permitted in the 
top course. They must constitute a good quality of “ paving-brick,” 
maintaining uniformity and regularity in shape to such a degree as 
will be consistent with a first-class pavement, and render satisfac¬ 
tion to the Engineer in charge. The bottom course of brick must 
be composed of a good quality of such as are known as “ sidewalk 
brick/’ The top course of brick, having been laid as above provid¬ 
ed, must then be covered with screened sand and rolled with a 
roller weighing at least two tons. During this final process of 
rolling the sand must continually be brushed into the pavement 
so as to effectuallv fill all crevices. All such work shall be under 
the supervision and subject to the approval of the Engineer. 

334. Specifications for brick pavements differ widely in their 
requirements. As yet no standard method of construction or of 
testing the quality of the brick has been arrived at. 

A variety of methods of construction are in vogue, and each one 
has its advocates and opponents. Thus we find in one place a foun¬ 
dation of sand, in another sand and boards, in another gravel, in 
others broken stone laid in the form of a Telford foundation, in 
others broken-stone concrete, and so on. 

As to the quality of the brick no definite requirements have 
been determined. In the absence of determined qualities it has. of 
course been impossible to adopt a uniform system of tests, and the 
majority of tests published are of little value from this want of 
uniformity. 

The specifications relating to the quality of the brick to be used 
are generally vague; the majority recite that “the brick used shall 
be hard, free from defects of any kind, manufactured and burned 
especially for street-paving purposes, be equal in all respects to the 
sample filed with the proposal, and subject to inspection and ac¬ 
ceptance or rejection by the engineer or inspector.” This state¬ 
ment of the qualities required defines in reality but very little. 
The term hard is an indefinite one; a hard brick in one locality 
may be known as a soft one in another. A\ itliout a definite state- 




194 


HIGHWAY CONSTRUCTION. 


ment as to what constitutes defects there may be differences of 
opinion as to whether or not they exist in a given article, as well as 
to the equality of goods furnished with the sample deposited. 

The characteristic qualities and strength of the material are not 
clearly defined, or in such manner as will enable the bidder to cor¬ 
rectly interpret the meaning. The power to accept or reject, 
although nominally in the hands of the engineer, is indefinite and 
unsupportable, because the acceptance or rejection cannot be made 
in accordance with known provisions and fixed rules. In the 
absence of recognized standards two courses are open in order to 
secure the desired qualities, avoid indefiniteness and controversy; 
namely, (1) to reserve the right to make, before awarding the con¬ 
tract, any test that the engineer may see fit to make, and award 
the contract in accordance with the results of such tests; or (2) 
prescribe in the specifications the definite tests to which the mate¬ 
rial will be subjected, with such reservations as to time and place 
as the exigencies of each particular place seem to demand. 





CHAPTER VII. 


BROKEN-STONE PAVEMENTS. 

335. As near as can be ascertained, the first broken-stone pave¬ 
ments were constructed in France in 1764 by one M. Tresaguet, 
who built many miles of such pavements in the latter part of the 
last century. In the early part of the present century two systems 
were introduced into England, the first by Telford, the second by 
Macadam. 

336. The name of Telford is associated with a rough stone foun¬ 
dation, which he did not always use, but which closely resembled 
that which had been previously used in France. Macadam disre¬ 
garded this foundation, contending that the subsoil, however bad, 
would carry any weight if made dry by drainage and kept dry by 
an impervious covering. The names of both have ever since been 
associated with the class of road which each favored, as well as 
with roads on which all their precepts have been disregarded. 

337. The following specifications show the difference in the 
methods of the inventors. 

338. Tresaguet’s Method, 1764 (Fig. 21).—“The bottom of 
the foundation is to be parallel to the surface of the road. The 
first bed or foundation is to be placed on edge and not on the 
fiat, in the form of a rough pavement, and consolidated by beat¬ 
ing with a large hammer; but it is unnecessary that the stones 
should be even one with the other. The second bed is to be equally 
placed by hand, layer by layer, and beaten and broken coarsely 
with a large hammer, so that the stones may wedge together and 
no empty spaces remain. The last bed, three inches in thickness, 
is to be broken to about the size of a nut with a small hammer, on 
a sort of anvil, and thrown upon the road without a shovel to form 
the curved surface. Great attention must be given to choose the 

hardest stone for the last bed, even if one is obliged to go to more 

195 


19G 


HIGHWAY CONSTRUCTION. 


distant quarries than those which furnish the stone for the body of 
the road. The solidity of the road depending on this latter bed, one 
cannot be too scrupulous as to the quality of the materials which 
are to be used for it.” 



Fig.20. FRENCH, previous to !775. 




Fig.22. TELFORD. 



339. Telford’s Method, 1824 (Fig. 22).—“ Upon the level bed 
prepared for the road materials a bottom course or layer of stones 
is to be set by hand in the form of a close firm pavement. The 
stones set in the middle of the road are to be seven inches in 
depth; at nine feet from the centre, five inches; at twelve feet 





































BROKEN-STONE PAVEMENTS. 


197 


from the centre, four inches; and at fifteen feet from the centre, 
three inches. They are to be set on their broadest edges lengthwise 
across the road, and the breadth of the upper edge is not to ex¬ 
ceed four inches in any case. All the irregularities of the upper 
part of the said pavement are to be broken off by the hammer, 
and all the interstices to be filled with stone chips firmly 
wedged or packed by hand with a light hammer, so that when the 
whole pavement is finished there shall be a convexity of four inches 
in the breadth of fifteen feet from the centre. 

“ The middle eighteen feet of pavement is to be coated with hard 
stones to the depth of six inches. Four of these six inches to be 
first put on and worked in by carriages and horses; care being 
taken to rake in the ruts until the surface becomes firm and con¬ 
solidated, after which the remaining two inches are to be put on. 

“ The whole of this stone is to be broken into pieces, as nearly 
cubical as possible, so that the largest piece in its largest dimen¬ 
sions may pass through a ring of two and one half inches inside 
diameter. 

“ The paved spaces on each side of the middle eighteen feet are 
to be coated with broken stones or well-cleaned gravel up to the 
footpath or other boundary of the road, so as to make the whole 
convexity of the road six inches from the centre to the sides of it, 
and the whole of the materials are to be covered with a binding of 
an inch and a half of good gravel free from clay or earth.” 

340. Macadam’s Method (Fig. 23).—Macadam omitted the foun¬ 
dation of large stones, claiming that it was not only useless but 
injurious; he placed on the natural soil a layer of stone broken 
equally into cubes of about one and a half inches in their greatest 
dimensions, and spread equally over the surface of the road to a 
depth of ten or twelve inches. Binding material was not used, the 
stone being left to work in and unite by its own angles under the 
traffic. Macadam preferred the test of weight to that of measure¬ 
ment, and insisted that no stone should weigh more than six 
ounces, which is the weight of a cube of one and a half inches of 
hard compact limestone; his overseers were provided with small 
scales and a six-ounce weight to test the larger stones. 

Although Macadam was the pioneer of good road construction 
in England, and from whose name the word macadamized is de- 
rived, it may be observed that he had been anticipated in the pro- 





198 


HIGHWAY CONSTRUCTION. 


mulgation of the system of a regularly-broken stone covering by 
Mr. Edgeworth, an Irish proprietor, whose treatise on roads, of 
which the second edition was published in 1817, contains the re¬ 
sults of his experiments on the construction of roads, with some 
useful rules. He advocated the breaking of the stones to a small 
size, and their equal distribution over the surface. He also recom¬ 
mended that the interstices should be filled with small gravel or 
sharp sand—a practice which, though condemned by Macadam, is 
now adopted by the best roadmakers. 

341. Since Telford and Macadam’s time the practice of road¬ 
making has been greatly improved by the introduction of rollers 
and stone-crushing machinery. 

342. Modern Telford. —On the natural-soil bed, properly graded, 
a layer of stones eight inches thick is set by hand, arranged and 
wedged as described by Telford. On the stone foundation so prepared 
a layer of broken stone of a size not exceeding three inches is evenly 
spread and rolled; the surface so rolled is covered with a layer of 
sand one-half inch thick, and the rolling continued; then a layer 
of stones not larger in any dimension than two inches is spread to 
a depth of four inches and rolled, followed as before with a layer 
of sand and also rolled. Finally a coating of clean sharp sand is 
applied, >well watered, and the rolling continued until the surface 
becomes smooth. The surplus sand is then swept off and removed. 

343. Modern Macadam pavements are constructed in the man¬ 
ner above described, only omitting the stone foundation, and the 
depth of the stone varies from four to twelve inches. 

344. Defects of the Telford System.—(1) No matter how care¬ 
fully the interstices between the foundation-stones are filled with 
chips, a large percentage of voids is left giving free access to 
water, thus defeating the object of the covering, which is to pre¬ 
serve the natural soil from contact with water. The pavement 
acts as a drain; the natural soil becomes saturated with water, 
and a slow but constant sinking of the bottom stone into the sub¬ 
soil and a slow but gradual rising of the natural soil takes place, 
the cohesion of the superstructure is destroyed, and it finally 
becomes a mass of mud and stones. 

(2) If the foundation be of a harder rock than the covering, it 
becomes an anvil on which the softer stones are pounded to pieces 
by the passing loads. 





BROKEN-STONE PAVEMENTS. 


199 


(3) The stone foundation unnecessarily increases the cost of 
construction. The roads of Central Park, N. Y., are excellent 
examples of the Telford system. They are of indefinite thickness, 
reposing on a bed of thoroughly drained earth; they were con¬ 
structed and are maintained at a cost that is prohibitory to an exten¬ 
sive use of such pavements. 

345. Defects of the Macadam System.—The broken stone laid 
as directed by Macadam cannot be impervious, because the inter¬ 
stices compose one half of the bulk of loosely spread stones, and no 
amount of rolling will reduce the voids more than one fourth; and 
as nature abhors a vacuum, the subsoil when moistened will rise up 
and fill the vacant space, and the weight of the traffic will force the 
lower stones down until the whole becomes a mass of mud and 
stones, as shown by the following analysis of a portion of the crust 
of the macadamized roads in the Mail, St. James Park, London: 

Analysis of Macadamized Road Crust. 

Mud.11-00 cu. ft. or 41.00 per cent 

Sand with pebbles not exceeding -j 3 g of an inch... 2.40 “ “ 9 

Stones from ^ to 4 inch. 6.56 “ “ 24 

“ “ i to 1 inch. 4.48 “ “ 16£ 

“ “ 1 to 2i inches. 2.56 “ “ 9£ 

Total volume.27.00cu.ft. or 100.00 percent 

From this analysis it appears that less than 9J per cent, say 
one tenth of the original stone, escaped underground, whilst 40 per 
cent of it was reduced to the state of mud. 

346. Advantages of Broken-stone Pavements. 

(1) Good foothold. 

(2) Eeasonably easy traction when in good condition. 

(3) Moderate first cost. 

(4) Comparatively noiseless. 

347. Defects Common to all Broken-stone Pavements. 

(1) Mud when wet. 

(2) Dust when dry. 

(3) Excessive cost of maintenance under heavy traffic. 

(4) Impossibility of keeping them clean. 

348. The foregoing defects condemn the use of broken stone 
for city streets, yet when properly built and maintained broken 










200 


HIGHWAY CONSTRUCTION'. 


stone forms the pleasantest, safest, and most economical road- 
surface known for city suburbs and country highways. 

Ideally perfect broken-stone road construction has never been 
attained, and never will be until our road constructors abandon 
obsolete precedents and construct road-coverings that will be 
adapted to the requirements of the traffic and impervious to water 
and frost. 

349. Essentials Requisite to Successful Construction.—The essen¬ 
tials requisite to the successful construction of broken-stone pave¬ 
ments may be summed up as follows: 

(1) The entire removal from the roadbed of all vegetable or 
perishable matter. 

(2) The removal of the natural soil to such depth as may be 
determined by its character, and by the thickness of the intended 
covering. 

(3) Sub-surface drainage wherever required. 

(4) The thorough compacting of the natural-soil bed. 

(5) The employment of sand or gravel for the foundation. 

(6) The employment of the best materials afforded by the 
locality. 

(7) The employment of unscreened stones. 

(8) The complete exclusion of clay or loam from the broken 
stone. 

(9) The employment of sand or gravel for binding, in sufficient 
quantity to fill the voids. 

(10) The thorough compacting of the broken stone with a 
roller of competent weight and suitable form. 

350. Erroneous Methods of Construction.—Broken-stone pave¬ 
ments can be made very unsatisfactory and defective by: 

(1) A permeable foundation. 

(2) By the use of excessively hard stones which no amount of 
rolling will consolidate. 

(3) By the use of improper binding material, such as loam and 
clay. 

(4) By an undue proportion of soft among hard stones. A 
small quantity (about one fourth) of soft stones judiciously mixed 
with the harder will be an undoubted advantage. 

(5) By employing stones of too large a size. 

(6) By screening the broken stone, thus removing the chips and 





B IiOK EN -STON E PAY EM ENTS. 


201 


dust which otherwise would assist iu filling the voids. Screening 
should not he practised, except when an injurious amount of clay 
or loam has become mixed with the stone. 

(7) By assorting the stone and laying it in layers according to 
the size of the stone. The practice of forming a road with strata 
of screened stone assorted in different sizes and growing smaller 
and smaller towards the top is erroneous; the smaller stone will find 
its way to the bottom, and the larger stone will work to the surface 
and ruts will be quickly formed. It will be porous, and no matter 
how heavily rolled it will be continually crumbling. 

(8) By covering the surface of the compacted stone with a layer 
of stone-dust. 

(9j By the use of an excessive quantity of binding material. 

(10) By the use of an excessive quantity of water when rolling. 

351. duality of the Stones.—The materials used for broken-stone 
pavements must of necessity vary very much according to the locality. 
Owing to the cost of haulage, local stone must generally be used 
especially if the traffic be only moderate. If, however, the traffic is 
heavy, it will sometimes be found better and more economical to 
obtain a superior material, even at a higher cost, than the local 
stone; and in cases where the traffic is very great, the best material 
that can be obtained is the most economical. 

352. The qualities required in a good road stone are hardness 
and toughness and ability to resist the disintegrating action of the 
weather. These qualities are seldom found together in the same 
stone. Igneous and silicious rocks, although frequently hard and 
tough, do not consolidate so well nor so quickly as limestone, owing 
to the sandy detritus formed by the two first having no cohesion, 
whilst the limestone has a detritus which acts like mortar in bind¬ 
ing the stones together. 

353. A stone of good binding nature will frequently wear much 
better than one without although it is not so hard. A limestone 
road well made and of good cross-section will be more impervious 
to wet than any other, owing to this cause, and will not disintegrate 
so soon in dry weather, owing partly to this and partly to the well- 
known quality which all limestone has of absorbing moisture from 
the atmosphere. Mere hardness without toughness is not of much 
use, as a stone may be very hard but so brittle as to be crushed to 





202 


HIGHWAY CONSTRUCTION. 


powder under a heavy load, when a stone not so hard but having 
a greater degree of toughness will be uninjured. 

354. The most efficient and economical rocks are basalt and 
syenite. Granite is unsuitable; the mica causes it to break up and 
grind away quickly. Gneiss is worse than granite. The slate rocks 
and mica schists are unsuitable. Clay slates are useless, as they 
crumble on exposure or degenerate into mud. The quartzose grits 
and silicious grits mixed with limestone form excellent roads. The 
carboniferous and transition limestones are fairly durable and make 
smooth and pleasant roads for light traffic and pleasure-drives. 
Field stone and river stone has been much used in some districts 
of England; they generally make a rough road, as they are com¬ 
posed of the hardest parts of those stones which have resisted the 
action of the weather, and are, though frequently very hard, of 
unequal hardness, so that they wear very irregularly. 

355. Coefficients of quality for various road materials have been 
obtained by the engineers of the French “Administration des 
Ponts et Chaussees.” The quality was assumed to be in inverse pro¬ 
portion to the quantity consumed on a length of road with the 
same traffic, and measurements were systematically made of the 
traffic and wear to arrive at correct results, these processes re¬ 
quiring great care and considerable time. Direct experiments on 
resistance to crushing and to abrasion and collision were made on 
673 samples of road materials of all kinds. The coefficients 
obtained by these experiments were found to agree fairly well with 
those arrived at by actual observation of the wear in the roads, and 
are summarized in Table XXXVIII. The coefficient 20 is equiva¬ 
lent to “ excellent,” 10 to “ sufficiently good,” and 5 to “ bad.” 

356. The experiments were conducted as follows: The apparatus 
employed to determine the resistance to wear consisted of cylindrical 
boxes of iron about 8 inches in diameter and 13 inches lono- 

to ^ 

mounted on an axle revolving horizontally, and so cranked as to 
hold the axes of the boxes at an angle of 30 degrees with the .axis 
of revolution. In each box was placed 5 kilograms of the broken 
materials to be tested, carefully cleansed from dust by washing, and 
the boxes put in motion at a rate of 2000 revolutions per hour. 
The stones rolled against one another, and were thrown from one 
end of the box to the other at each revolution. After 5 hours or 
10,000 revolutions the boxes were opened, the detritus resulting 



BROKEN-STONE PAVEMENTS. 


203 


from tlie rubbing and collision was carefully collected and sorted, 
and the weight of all of less diameter than -fa inch, compared with 
that of the original samples, gave the degree of wear. It was found 
that the best materials seldom gave less than 20 grams of detritus 
per kilogram, and the coefficient of 20 was, therefore, adopted 
for materials having that proportion of wear. For other materials 
the coefficient was derived from the proportion 

Grams of detritus :: 20 : 20 :: coefficient. 

Resistance to crushing was determined by means of an hydraulic 
press. Experience having shown that cubes of the hardest ma¬ 
terials rarely resisted more than 3000 kilograms per square centi¬ 
meter (equal to about 19 tons per square inch) the coefficient of 20 
was given to materials presenting that degree of resistance, and 
other coefficients were derived from the proportion 

3000 : crushing weight per square centimeter :: 20 : coefficient. 

In the experiments every precaution to insure accurate results 
was taken. When the materials were already rounded, as pebbles, 
they did not wear much in the machine, and obtained a coefficient 
far above their value; and there were anomalies with a few other 
materials, such as chalk flints with a softer coating, and stones with 
cavities. The size to which the stones were broken did not seem to 
have much influence on the wear. 


TABLE XXXVIII. 
Coefficients of Quality. 


Materials. 

Coefficient of Wear. 

Coefficient of 
Crushing. 

Basalt. 

12.5 to 24.2 

12.1 to 16 

Porphyry. 

14.1 “ 22.9 

8.3 “ 16.3 

Gneiss.'. 

10.3 “ 19.0 

13.4 “ 14.8 

Granite. 

7.3 “ 18.0 

7.7 “ 15.8 

Syenite. 

11.6 “ 12.7 

12.4 “ 13.0 

Siair. 

14.5 “ 15.3 

7.2 “ 11.1 

Quartzite... 

13.8 “ 30.0 

12.3 “ 21.6 

Quartzose sandstone. 

14.3 “ 26.2 

9.9 “ 16.6 

Quartz. 

12.9 “ 17.8 

12.3 “ 13.2 

Silex. 

9.8 “ 21.3 

14.2 “ 17.6 

Chalk flints. 

3.5 “ 16.8 

17.8 “ 25.5 

Limestone. 

6.6 “ 15.7 

6.5 “ 13.5 

























204 


HIGHWAY CONSTRUCTION. 


357. Size of Stones.—The stones should be broken into frag¬ 
ments as nearly cubical as possible. The size of the cubes will 
depend upon the character of the rock. If it be granite or trap, 
they should not exceed 14 inches in their greatest dimensions; if 
limestone, thev should not exceed 2 inches. 

358. The smaller the stones the less the percentage of voids. 
Small stones compact sooner, require less binding, and make a 
smoother surface than large ones. 

359. It is not necessary nor is it advisable that the stones should 
be all of the same size; they maybe of all sizes under the maximum. 
In this condition the smaller stones fill the voids between the larger 
and less binding is required. 



PlG. 24-SIZE AND SHAPE OF STONE FOR BROKEN- 

STONE PAVEMENTS. 

The proper shape of broken stone is shown in Fig. 24. 

360. Breaking the Stone.—Breaking stone for the purpose of 
using it as a road-covering was until quite recently always effected 
by hand; now by the use of machinery it is more quickly and 
cheaply broken. 

361. Hand-broken stone still finds favor with European en¬ 
gineers; they claim that it is better broken and has sharper angles 
than that broken by crushing: and in many districts the occupa¬ 
tion affords employment for persons who otherwise would be 
thrown upon the public for support. 

362. In breaking stone by hand the breaker sits and strikes the 
stone with a small cast-steel chisel-faced hammer, weighing about 




BROKEN-STONE PAVEMENTS. 


205 


one pound, fixed at the end of a long, straight-grained but flexible 
ash stick. The breaker also has another hammer, weighing about 
five pounds, with which he reduces the size of the large stones before 
breaking them into proper size. Each breaker is furnished with a 
gauge-ring through which the stones must pass in every direction. 

363. The great cost of hand-broken stone led to the employ¬ 
ment of machine crushers; their use effected a reduction in the 
cost of from 50 to 200 per cent, and increased the amount of daily 
output from 1 to 50. 

364. The objections to machine-broken stone are principally: 

(1) Want of uniformity in the size of stones. 

(2) The stone is frequently flaky with rounded edges, which is 
a very disadvantageous form for compacting. 

(3) Very tough stones have frequently to be passed several 
times through the machine before they get properly broken. 

(4) Very soft stones are crushed to powder. 

365. Cost of Breaking Stone.—The cost of breaking stone by 
hand will vary considerably in different localities on account of the 
character of the stones to be broken and the value of labor. 

366. The average amount of stone broken by a good stone- 
breaker is given by Mr. Codrington in his work on the Mainte¬ 
nance of Macadamized Roads as follows: Hard silicious stones and 
igneous rocks, 1 to 14- cubic yards per day; granite, 4 cubic yard pei 
day; river gravel, field-stones, or flints, 3 to 4 cubic yards per day. 

" 367. The cost of a stone-crushing plant and expense of operat¬ 
ing may be taken as follows: 

Cost of crusher, engine, and boiler set up, complete 

Cost of operating: 

1 ensnneman and fireman .. 

2 laborers feeding. 

2 tons of coal .. 

Oil, waste, etc... 

Repairs. 


.$2500.00 

$3.00 

3.50 

8.00 

2.00 

10.00—$26.50 


The product will vary with the toughness of the stone to be 

broken and the size of the machine. 

368. The wear and tear of a stone-crusher is very considerable; 

it has been known to reach as high as 62.5 per cent of the fiist cos 

of the machine in one year. 











206 


HIGHWAY CONSTRUCTION. 


369. To make a stone-breaking machine pay, it is necessary— 

(1) To give it nearly constant work. 

(2) To exercise care in feeding, to give a sufficient supply with¬ 
out allowing an undue quantity of stone to pass in at one time. 

(3) That the machine shall be so located as to reduce to the 
minimum the expense of handling both the unbroken and the 
broken stone. 

The dimensions and capacity of several crushers are given in 
Chap. XXIII. 

370. It is impossible to estimate the cost of getting the un¬ 
broken stone to the crusher and the broken stone back to the road, 
for that depends entirely upon the distance which must be trav¬ 
ersed in cartage and the condition of the grounds over which the 
loads are hauled. If the loads have to be hauled a considerable 
distance to or from the crusher, or if heavy grades have to be as¬ 
cended or rough ground traversed, the time occupied in hauling 
each load will be increased and less can be hauled in a day, thus 
lessening the work done by horses and drivers for each day’s wages. 

Where stone is to be obtained in more than one place along the 
line of the projected road, it is sometimes more economical to take 
the crusher to the stone than to have to haul the broken stone a 
great distance. For this purpose the crusher can be mounted on 
wheels and the steam roller used to haul and drive the crusher, 
without the expense of a fixed plant for crushing stone. 

371. Cost of Quarrying and Crushing Stone. —The report of the 
Board of Street Commissioners of the city of Hartford, Conn., for 
the year 1890 contains the following table of the cost of quarrying 
and crushing stone for the past ten years. 

The increase in the cost of quarrying and crushing stone during 
the past year is in part chargeable to the extra cost of hauling the 
stone to the crushers, on account of the added distance at which 
the stone was procured, also in part by the expense connected with 
the opening of new quarries. 

372. Voids in the Broken Stone. —The voids of broken stone in 
which the size and shape of the pieces are nearly uniform are about 
one half the mass. If the pieces are not uniform, the voids are 
about four tenths of the mass. The voids in gravel vary, but aver¬ 
age about one half of the mass. The greatest amount of rolling 
will not reduce the voids more than one half of the primitive bulk. 




BROKEN-STONE PAVEMENTS. 


207 


TABLE XXXIX. 

Cost of Quarrying and Crushing Stone. 


Year. 

Cost of 
Quarrying per 
cubic yard. 

1881. 

.655 ct. 

1882. 

.781 ct. 

1 ^83••••••«• 

.638 ct. 

1884.. 

.665 ct. 

1885. 

.658 ct. 

1886. 

. 590 ct. 

1887. 

. 595 ct. 

1888. 

.658 ct. 

1889. 

.694 ct. 

1890. 

.889 ct. 


Cost of 
Crushing per 
cubic yard. 

Cost of 
Carting to 
Breaker per 
cubic yard. 

.536 ct. 

.283 ct. 

.348 ct. 

.237 ct. 

.265 ct. 

.247 ct. 

.372 ct. 

. 228 ct. 

.342 ct. 

. 224 ct. 

. 289 ct. 

.233 ct. 

.345 ct. 

.281 ct. 

.221 ct. 

. 288 ct. 

.319 ct. 

. 263 ct. 

.407 ct. 

.301 ct. 


Total Cost of 
Crushed Stone 
at the Quarry 
per cubic yard. 

Average Cost 
Delivered on 
the Streets 
per cubic yard. 

$1.47 

$1.70 

1.36 

1.87 

1.15 

1.59 

1.26 

1 70 

1.23 

1.66 

1.12 

1.65 

1.22 

1.64 

1.17 

1.63 

1.28 

1.69 

1.597 

2.045 


A well-rolled road-covering contains from 70 to 80 per cent of 
stone. 

373. Determination of the Voids in Broken Stone.—The pro¬ 
portion of voids may be determined by experiment in either of the 
following ways: (1) Determine the specific gravity of the material, 
and from that the weight of a unit of volume of the solid. Weigh 
a unit of volume of the loose material. The difference between the 
weights divided by the first gives the proportion of the voids. 
(2) Wet the loose material thoroughly, fill a vessel of known capac¬ 
ity with it, and then pour in all the water the vessel will contain. 
Measure the volume of water required and divide this by the 
volume of the vessel; the quotient represents the proportion of 
voids. 

The smaller the stone is broken the less the percentage of voids 
and the heavier a cubic yard will weigh. 

374. Weight of Broken Stone.—To ascertain the weight of a 
cubic yard of broken stone, multiply the weight of a cubic 
yard of the given stone by the proportion of voids (usually 0.50); 
the result will be the weight of a cubic yard of the stone when 
broken. 

375. Area covered by One Cubic Yard of Broken Stone.—A 

cubic yard of ordinary broken stone will, when properly spread, 
cover an area of about 32 square yards of surface of a roadway. 

Since a cubic yard of loose broken stone contains only one half 



























208 


HIGHWAY CONSTRUCTION. 


of its volume, or 13^ cubic feet of solid stone, its weight, allowing 
12 cubic feet of solid granite to one ton, is approximately 


1 X 


13.5 

12.0 


= 1^ ton. 


Again, one cubic yard is equivalent to 3G square yards 1 inch deep; 
and 1 ton of stone laid without compression to a depth of 1 inch 

covers an area of 36 X ~ = 32 square yards. When the stone is 

1 & 

laid and rolled the primitive volume is reduced by about one fourth; 
and 1 ton of rolled stone laid to a depth of one inch covers an area 
one fourth less than 32, or 32 X f = 24 square yards. 

376. To Find the Area that can be covered by One Ton of Stone, 
when the Thickness of the Layer is given.—Divide 32 by the thick¬ 
ness of the layer in inches if unrolled; or divide 24 by the thick¬ 
ness of the layer in inches when rolled. The quotient is the area 
in square yards. 

377. To Find the Area that can be covered by One Cubic Yard 
of Broken Stone, when the Thickness of the Layer is given.—When 

the stone is not rolled, divide 36 by the thickness in inches; the 
quotient is the number of square yards that can be covered. When 
the stone is rolled, divide 27 by the final thickness in inches; the 
quotient is the number of square yards. 

378. Thickness of the Broken Stone.—The offices of the stone 
are to endure friction and shed water; its thickness must therefore 
be regulated by the quality of the material and the amount of the 
traffic, and not by any consideration as to its own independent 
power of bearing weight. Macadam considered 10 inches as suffi¬ 
cient for any traffic on any substratum : experience has proved this 
true in the well-drained and well-kept roads of Europe. 

379. The proper rule is to vary the thickness according to the 
traffic and the grade. Roads of sharp descent do not require as 
thick covering as those having flat grades. 

Mr. J. Owen, County Engineer of Essex County, N. J., 
adopted the following thicknesses with good results: 


For grades flatter than 1 % . 10 inches 

“ “ between 1 % and 4#. 8 “ 

“ “ over 4#. 6 “ 








BROKEN-STONE PAVEMENTS. 


209 


The roads of Bridgeport, Conn, (upwards of 50 miles), built 
under the direction of Mr. B. I). Pierce, are, with the exception of 
two short pieces, only 4 inches thick. These roads are subjected to a 
regular traffic of loads averaging G000 pounds each; they give entire 
satisfaction to the public using them, and an ordinary team hauls a 
net load of 3000 pounds over them. 

380. Many roads of 4 and G inches thickness have been built that 
have not proved satisfactory. Their failure is generally attributed 
to their thinness. This is erroneous; the fault does not always lie in 
the thinness of the stone covering, but in the method of construc¬ 
tion followed. The thin roads that fail are as a rule made bv 
throwing the broken stone on an undrained and unrolled earth 
roadway, frequently without even removing the mud which covers 
its surface. In some few cases the stones are rolled with a horse 
roller, but in the majority the stone is left to be consolidated by 
the traffic. If roads are to be built in this manner, they must be 
massive; but no matter how massive they be made, they will 
have no cohesive strength, they will never be impervious to the 
mud from below or the rain from above, and will always be unsatis¬ 
factory. 

381. Sand Core for Broken-stone Pavement.—On a well-drained 
foundation a sand or gravel core will be found as mechanically 
serviceable as the most costly stone foundation. Such a core covered 
with a layer of stone measuring when compacted 4 inches thick 
will form a finer and more lasting surface than a greater thickness 
of stone laid upon the earth soil and compacted. Telford was 
aware of this fact; he was willing to prevent by almost any means 
available the coming in contact of his road material with the earth 
subsoil, and suggested gravel, sand, or chalk as alternatives to 
bottoming stones. A requisite, whatever the medium, was that “ this 
bottoming should be made perfectly firm and regular, so as to re¬ 
ceive the top workable metal of equal thickness.” Thus, although 
he always advised a paved bottom when it could be had, many miles 
of roadway were made under Telford’s direction without the paved 
bottom with which his name is associated. 

382. The quantity of broken stone required per mile of road for 
different widths and thicknesses is given in Table XL. 

383. Spreading the Stone.—The stone should be hauled upon 
the roadbed in broad-tired two-wheeled carts and dumped in heaps, 




210 


HIGHWAY CONSTRUCTION. 


TABLE XL. 

Number of Cubic Yards of Broken Stone required per Mile of 

Road. 


Width of Pavement in Feet. 


Stone in 
Inches. 

8 

16 

24 

30 

32 

10 

48 

60 

4 

645 

1,290 

1,935 

2,421 

2,580 

3,225 

3.870 

4.842 

6 

968 

1,935 

2,903 

3,632 

3,872 

4 840 

5,808 

7,264 

8 

1,290 

2,580 

3,870 

4,842 

5,160 

6,450 

7,740 

9,684 

10 

1,613 

3,225 

4,838 

6,053 

6,452 

8.065 

9,678 

12,106 

12 

1,935 

3,870 

5,805 

7,263 

7,740 

9,675 

11,610 

14,526 

14 

2,258 

4,515 

6,773 

8,474 

9,032 

11,290 

13,548 

16,948 

16 

2,580 

5,160 

7,740 

9,684 

10,320 

12,900 

15,480 

19,368 


and be spread evenly with a rake in a layer of as nearly uniform 
thickness as may be. 

384. Thickness of the Layers.—The thickness of the layers will 
depend upon the final thickness of the covering. If the finished 
thickness is to be 6 inches, each layer should be of a depth of 4^ 
inches. 

385. Macadam insisted that the stone should not be laid in 
shovelfuls but scattered over the surface, one shovelful following 
another and spreading over considerable space. His object in this 
was to avoid an accumulation of soft stones at one spot, for the 
rocks from which the stone was obtained were not of uniform hard¬ 
ness, but of all qualities gathered from adjoining fields. The 
application of this method to stone of uniform quality would be 
detrimental and have the same effect as screening. 

386. Binding.—One half of the volume of loosely sjoread broken 
stone is space, and no amount of rolling will reduce it more than 
one half; therefore to thoroughly consolidate the broken stone some 
fine material must be added. It may consist of the fragments and 
detritus obtained in crushing the stone. When this is insufficient, as 
will be the case with the harder rocks, the deficiency may be made 
up of clean sand or gravel. The proportion of binder should slightly 
exceed the voids in the aggregate; it must not be mixed with the 
stones, but should be spread uniformly in small quantities over the 
surface and rolled into the interstices with the aid of water and 
brooms. 































BROKEN-STONE PAVEMENTS. 


211 


387. It is a useless refinement to screen the broken stone; it 
should be placed in the road as it comes from the breakers, care be¬ 
ing taken to prevent the admixture of clay or loam, the presence of 
which in large quantities is extremely injurious. When present to 
an injurious extent, the stone must be screened. 

388. By using a large quantity of binding material mixed with 
the stones the amount of rolling is lessened, but at the expense of 
durability. If there is an excess of binding material in the joints 
of the stones, the first heavy rain washes it out and the surface of 
the roadway quickly goes to pieces. 

389. The French engineers use clay, sand, or earth from the 
road excavation when such is suitable, in the proportion of one 
fourth to one sixteenth of the bulk of the stone. They apply it 
after the steam roller has been once over the broken stones. 

390. Necessity of Binding Material.—With reference to the 
necessity of binding material, the following facts are interesting. 

Mr. Wm. H. Grant, Superintending Engineer of the New York 
Central Park, in his report upon the park roads, says: 

“ At the commencement of the macadam roads, the experiment 
was tried of rolling and compacting the stone by a strict adherence 
to Macadands theory, that of carefully excluding all dirt and foreign 
material from the stones, and trusting to the action of the roller 
and the travel of teams to accomplish the work of consolidation. 
The bottom layer of stone was sufficiently compacted in this wa}' 
to form and retain, under the action of the rollers (after the com¬ 
pression had reached its practical limit), an even and regular sur¬ 
face; but the top layer, with the use of the heavy roller loaded to 
its greatest capacity, it was found impracticable to solidify and 
reduce to such a surface as would prevent the stones from loosening 
and being displaced by the action of wagon-wheels and horses’ feet. 
No amount of rolling was sufficient to produce a thorough binding 
upon the stones, or to cause a mechanical union and adjustment of 
their sides and angles together as to enable them mutually to assist 
each other in resisting displacement. The rolling was persisted in 
with the roller adjusted to different weights up to the maximum 
load (12 tons), until it was apparent that the opposite effect from 
that intended was being produced. The stones became rounded by 
the excessive attrition they were subjected to, their more angular 
parts wearing away, and the weaker and smaller ones being crushed. 




212 


H1GHWAY CONSTRUCTIOX. 


“ The experiment was not pushed beyond this point. It was 
conclusively shown that broken stones of the ordinary sizes and of 
the best quality for wear and durability, with the greatest care and 
attention to all the necessary conditions of rolling and compression 
would not consolidate in the effectual manner required for the sur¬ 
face of a road while entirely isolated from and independent of 
other substances. The utmost efforts to compress and solidify them 
while in this condition, after a certain limit had been reached, were 
unavailing.” 

391. Mr. Deacon, Engineer of Liverpool, England, describes the 
effect of binding material as follows: 

“Under a 15-ton steam roller preceded by a watering-cart, 1200 
yards of trap-rock macadam, without binding, can only be moder¬ 
ately consolidated by twenty-seven hours' continuous rolling. If 
the trap-rock cliippings from the stone-breaker are used for binding, 
the same area may be moderately consolidated by the same roller in 
eighteen hours. If silicious gravel from f inch to the size of a 
pin’s head, mixed with about one fourth part of macadam sweepings 
obtained in wet weather, be used, the area may be thoroughly con¬ 
solidated in nine hours. 

“ Macadam laid according to the last method wears better than 
that laid by the second, and that laid by the second much better 
than that laid by the first.” 

392. Watering.—Wetting the stone expedites the consolidation, 
decreases crushing under the roller, and assists the filling of the 
voids with the binder. It should be applied by a sprinkler and not 
be thrown on in quantity or from the plain nozzle of a hose. 

Excessive watering, especially in the earlier stages, tends to soften 
the foundation, and care should be exercised in its application. 

393. Compacting the Broken Stone.—Three methods of com¬ 
pacting the broken stone are practised: (1) by the traffic passing 
over the road; (2) by rollers drawn by horses; (3) by rollers pro¬ 
pelled by steam. 

394. The first method is both defective and objectionable. 
(1) It is destructive to the horses and vehicles using the road. (2) 
It is wasteful of material; about one third of the stone is worn away 
in the operation. (3) Dung and dust are ground up with the stone, 
and the road is more readily affected by wet and frost. 

395. The first recorded allusion to the consolidation of roads 




BROKEN-STONE PAVEMENTS. 


213 


by rolling seems to have been made in 1619 by John Shotbolt in 
England. The first practical application of rollers appears to have 
been made by the French engineers in 1829. Their first applica¬ 
tion in England appears to have been made by Sir John E. Bur- 
goyne. Since these dates rolling has been universally adopted on 
the continent of Europe, not as a refinement but as a necessity, and 
no road is considered complete until it has been thoroughly com¬ 
pacted by a roller. 

396. Advantages of Rolling.—The advantage of rolling broken- 
stone pavement may be summed up as follows: 

(1) The saving of wear and tear of horses and vehicles. Roads 
should be made for the traffic and not by it. 

(2) Comfort of persons using the roads. 

(3) Economy, as a saving of from 30 to 50 per cent is effected 
by reason of the roads being better made, thus obviating the neces¬ 
sity for such frequent sweeping and scraping. If a portion of a 
road that has not been rolled is broken up and the material washed, 
it will be found that as much as half of it is soluble matter, mud, 
dirt, and fine sand. The stones having been thrown loosely upon 
the road-bed have lain so long before becoming consolidated by the 
traffic, and have undergone in the mean time such extensive abra¬ 
sion, that the proportion of mud, dirt, and pulverized material is 
increased to that extent, and the stones are really only stuck to¬ 
gether by the mud. This accounts for the fact that although an 
unrolled road may indeed after long use have a surface that is 
pretty good and hard in dry weather, and may offer then a very 
slight resistance to traction, yet it will quickly become soft and 
muddy when there is rain. By the employment of a roller of com¬ 
petent weight the stones are well bedded at once, and the surface is 
consolidated into a sort of stone felt capable of resisting most effect¬ 
ually the action of the traffic, and containing the smallest quantity 
of soluble matter to form mud in wet weather. 

(4) The avoidance of cruelty to horses, as in the case of newly 
metalled unrolled roads. 

397. Horse Rollers.—Rollers drawn by horses are unsatisfactory 
for compacting the broken stone. They are expensive to use, re¬ 
quiring a large number of horses and attendants. The horses' feet 
displace as many stones as the roller compacts, and if they are of 
^great weight they become clumsy and difficult of manipulation. 




214 


HIGHWAY CONSTRUCTION. 


398. Steam Rollers—Steam rollers were first introduced in 
I860, since which time they have been almost universally adopted 
on account of the superiority and economy of the work done. They 
are simply a locomotive mounted on broad and heavy wheels. They 
can be made of any desired weight. Those now in use vary from eight 
to thirty tons. Ten tons appears to be the most desirable weight. 
Heavier rollers are unwieldy, and from their great weight are liable 
to damage the sewers, water, or other underground service-pipes 
that may be in the roadway. 

399. The advantages of steam rolling may be summed up as 
follows: 

(1) They shorten the time of construction. 

(2) A saving of road metal, (a) because there are no loose stones 
to be kicked about and worn; (b) because there is no abrasion of 
the stones, only one surface of the stone being exposed to wear; 
(c) because a thinner coating of stone can be employed; (d) because 
no ruts can be formed in which water can lie to rot the stone. 

(3) Steam-rolled roads are easier to travel on account of their 
even surface and superior hardness and have a better appearance. 

(4) The roads can be repaired at any season of the year. 

(5) Saving both in materials and manual labor. 

400. Form of Rollers.—The advantage of the present form of 
rollers is generally overestimated. The heaviest roller in use does 
not exert the same pressure per inch of width nor in the same man¬ 
ner that a heavily loaded wagon does. An ordinary cart, loaded, 
presses with a weight of about 1000 pounds per inch width of tire; 
a loaded four-wheeled wagon exerts a pressure of about 850 pounds 
per inch, and a 10-ton roller about 450 pounds: so that as far as 
the surface of the roadway is concerned the roller affects it the least 
of any of the above loads. Therefore a roller should be as heavy 
per inch of width as a loaded wagon-wheel is per inch of tire, else 
the wagon-wheels will exercise more pressure per inch, and conse¬ 
quently will cut into the rolled surface and produce ruts. 

The wheels of the rollers now in use have too wide a bearing on 
the road surface. The smaller soft spots are bridged over and remain 
unseen until the road is completed and thrown open for use. The 
traffic will quickly find these soft spots, and hollows and ruts will 
form. To obviate this and obtain the best effect from rollers, thev 
should be constructed with both front and rear rolls. The front roll 





BROKEN-STONE PAVEMENTS. 


215 


should be formed of disks, having diameters varying about six inches, 
set alternately on the axle. The rear roll may be formed of two or 
more disks of uniform diameter. The ridges left by the front roll 
will be levelled by the rear roll. The etfect produced by a roller of . 
this form will approximate more nearly the effect of loaded wagon- 
wheels. 

401. The driving rolls of steam-rollers usually have holes bored 
in their faces to receive spikes, in order that they may be used for 
breaking up or disintegrating the road-surface. These, however, 
apparently do not answer; the working of a machine in this man¬ 
ner shakes and strains it considerably, and the holes in the rollers, 
which are plugged with wood when not in use for this purpose, are 
objectionable; the plugs wear out and the road metal gets into 
holes, and the surface of the road is picked up as the rolling pro¬ 
ceeds. Besides this, the spikes seem to have no effect unless the 
surface of the roadway being operated upon is soft. 

402. The steepest gradient upon which a steam roller can be 
operated appears to be 1 in 6, but this requires a very heavy pres¬ 
sure of steam; 1 in 14 or about 7 $ seems to give no trouble in 
rolling either up or down. 

403. Cost of Maintaining Steam Rollers.—The annual cost of 
maintaining steam rollers as given in the reports of city engineers 
is as follows: 


Hartford, Conn. 


One 10-ton roller. .. .$4,000.00 

Wages of engineer and tenders. $888.57 ] 

Coal (40,730 pounds) . 111.01 

Wood (5| cords). 31.20 

Water for boiler. 12.00 

Repairs, tools, etc. 210.70 

Oil, waste, and packing. 43.59 

Insurance. 15.00 


Total for year.$1,312.07 

Toledo, Ohio. 

Wages. $951.50 

Fuel, supplies, and repairs. 316.29 


Total for year...$1,267.79 

Duluth, Minn. 

Wages, fuel, repairs, etc . $2,087.41 




















216 


HIGHWAY CONSTRUCTION. 


In England the cost per annum for 9 hours per day is abouj 

$ 2000 . 

404. Amount of Rolling.—The number of superficial yards 
• rolled per day must vary extremely with circumstances—the class 
of material, the amount of binding and water used, the gradient and 
pressure of steam maintained, and the amount of rolling considered 
necessary. The number of square yards rolled varies from 500 to 
3000 per diem, the average of 42 English towns being 1105 square 
yards per diem. 

In Paris 2 to 3.75 ton-miles of roller are applied to every cubic 
yard of stone. The weight of steam rollers per inch of run is speci¬ 
fied to be 448 and 336 pounds, and for horse rollers 263 pounds. 
The ton-miles necessary to make a square yard of porphyry wheel¬ 
way, or to compact a cubic yard of the same metal, is given as 
follows: The mean for two models of machines weighing 448 
pounds per inch run was, per square yard, with the thickness of 
3.9 inches, 0.41 ton-mile; while for the roller of 336 pounds, with 
a thickness of 2.8 inches, 0.234 ton-mile was required, or 3.78 and 
2.99 ton-miles per cubic yard respectively; and for horse rollers, 
where the thickness was 2.6 inches, the ton-miles required were 
0.194 per square yard and 2.69 per cubic yard. The amounts con¬ 
solidated per ton per hour are in the following proportions: 467 for 
the heavy rollers, 539 for the light rollers, and 297 for the horse 
roller, and the number of passages of the rollers were 98.5, 75, and 
92. The maximum speed is stated at 2.3 miles per hour. The roll¬ 
ing is done by contract (the city furnishing the water) at a rate 
per ton-mile varying from 15.26 to 7.63 cents, according to the 
amount, with an increase of one third in price where the grade 
exceeds 6 per cent. 

The Southern Boulevard, New York City, constructed by Mr. 
E. P. North, received 0.859 ton-mile per square yard or 5.177 ton- 
miles per cubic yard. 

From careful experiments with blue limestone in England, it 
has been found that to obtain consolidation with the usual coating 
of two stones in thickness (each cubic yard broken to 2|-inch 
gauge, and made to cover about 17 square yards of surface), the 
steam roller must traverse a patch equal to its own width about 
35 times. From this it appears that a cubic yard of broken stone 
requires 1£ ton-miles to produce consolidation. For binding about 






BROKEN-STONE PAVEMENTS. 


217 


5 per cent, of well-weathered road-scraping was used, being spread 
over the surface when consolidation was nearly effected. Without 
the use of binding, consolidation was found impossible. 

The only guide for the proper amount of rolling is that it must 
be continued until the stones cease to creep in front or sink under 
the rolls, and the surface has become smooth and firm. 

405. Manner of Applying the Roller.—The stone should be 
spread in a uniform layer 4| inches thick. This depth will consoli¬ 
date better than either thicker or thinner. Commence the rolling 
at the sides, and continue it until such a degree of firmness is 
attained that when the roller passes over the centre or crown of 
the road, its weight, which tends to spread the metal or make it 
work off towards the sides, may be resisted by their consolidation. 

The surface of a well-constructed broken-stone road should, 
after being rolled, look almost like an encaustic pavement. 

The rolling should be done slowly, as nothing is gained by a 
rapid motion; the fuel consumption being considerably increased 
without any advantage to the work. 

406. Cost of Rolling.—The average cost of rolling varies con¬ 
siderably by reason of the amount of rolling considered necessary. 
In England it varies between one and two cents per square yard. 
In the United States it varies between 0.015 to 14 cents per square 
yard. 

407. Cost of Broken-stone Pavement.—What the cost of broken- 
stone pavements will be must depend upon the accessibility and 

TABLE XLI. 

Cost of Broken stone Roads. 


Locality. 

Thickness 
of Stone. 
Inches. 

Width of 
Pavement. 
Feet. 

Method. 

Cost per 
Mile. 

Bridgeport, Conn. 

. 4 

18 to 20 

Macadam 

$3,000 

Fairfield, Conn. 

4 

20 

Macadam 

5,000 

Fanwood, Conn... 

12 

16 

Telford 

9,530 

Franklin Township, N. J... 

4 

15 

Macadam 

4,700 

Kingston, R. I. 

8 

16 to 20 

Macadam 

5,500 

Linden Township, N. J. 

12 

16 

Telford 

11,600 

Plainfield, N. J.. 

4 to 6 

16 

Macadam 

3,000 

Rahway, N. J. 

12 

16 

Telford 

9,349 

Westfield, N. J. 

12 

16 

Telford 

9,640 

Union Township, N. J. 

12 

16 

Telford 

11,900 

























218 


HIGHWAY CONSTRUCTION. 


cost of material and labor, which will be quite variable. In Tables 
XLI and XLII is given the cost in different localities in the United 
States. 

TABLE XLII. 

Extent and Cost of Broken-stone Pavements in some of the 
Principal Cities of the United States in 1890. 


Cities. 

Extent. 

Miles. 

Cost per Square Yard 

St. Louis, Mo. 

271.76 

$0.51 

0.90* to 1.70f 
0.75 to 1.25 

Chicago, Ill. 

226.67 

Boston, Mass.... 

172.00 

Nashville, Term. 

111.00 

0.45 

Providence, R. I. 

110.00 

Philadelphia, Pa. . 

90.80 


Hartford, Conn . 

64.00 

1.00 

Syracuse, N. Y . 

50.00 

0.69 to 1 08 

Rochester, N. Y . 

46.00 

1.25 

Paterson, N. J. 

38.00 

0 45 

New Haven, Conn. 

28 50 

0 50 to 1.25 

New Y r ork, N. Y. 

25.34 

1.00 to 1.50t 

Worcester, Mass. 

20.00 

Cambridge, Mass. 

20.00 

0.70 

Harrisburg, Pa. 

20 00 

Toledo, Ohio. 

10.39 

1.23 

Burlington, Vt... 

7.74 

Washington, D. C. 

6.00 


Richmond, Ya. 

5.72 

0.75 § 

Utica, N. Y... 

2.62 

Oswego, N. Y. 

2.18 


Albany,' N. Y. 

1.71 


Milwaukee, Wis. 

1.16 


Los Angeles, Cal. 

1 00 

1.17 

Schenectady, N. Y. 

0.75 

Cincinnati, Ohio. 

1.25 IT 

Duluth, Minn. 

44.00 

Jersey City, N. J.. . 

1 50 • 


East Saginaw, Mich. 

1.00 


Springfield, Mass. 

15 00 


Chelsea, Mass. 

5 00 


Dubuque, Iowa. 

34 60 


Toronto, Can. 

37.27 

20 00 


Mobile, Ala. .. 


Lowell, Mass. 

10.00 

18.33 % 
10.84 X 
4.50 X 

l.u x 

0.50 X 


St. Louis, Mo. 

0.84 

1.75 

Newark, N. J. 

Kingston, N. Y. 

Toledo, Ohio. 

Trenton, N. J. 





* Limestone and gravel 10 inches deep. f Crushed granite topping. 
t Telford. § 12 inches deep. 18 inches deep. 






















































BROKEN-STONE PAVEMENTS. 


219 


408 Difference in the Cost of European and American Broken- 
stone Pavements.—As an example exhibiting the difference in the 
cost of constructing macadam roads in Europe and the United 
States, we select a first-class highway of the broadest type, one 
which was built about ten years ago over a level expanse between 
the villages of Langenfeld and Burgwald, Germany. The road in 
question is 2100 meters (6888 feet) long, 26 \ feet in width, the 
macadamized wagon track 13 \ feet wide and 8£ inches thick. With 
labor estimated at 36 cents per day except for stone masonry, which 
costs in country districts from 60 to 75 cents per day, the construc¬ 
tion account of this road foots up as follows: 



Germany. 

America. 

Grading roadway. 

$707.61 

89.96 

154.70 

3617.35 

11.38 

75.68 

155.65 

61.88 

369.85 

49.98 

$1743.00 

268.88 

464.10 

7843.50 

34.14 

151.36 

155.65 

185.64 

784.35 

49.98 

Planting and turfing slopes. 

Bridges and culverts. 

Macadamizing... 

Milestones etc. 

Tools... 

Damages to adjacent property during work ... 
Tree-nlantintr. 

Snnprint.pnrionno of oonstmotion. 

Incidentals. 

This is eauivalent to about. 

$5324.04 
$4092.00 
per mile 

$11680.00 
$8947.60 
per mile 



409. Wear of Broken-stone Pavements.—The wear of road ma¬ 
terials resulting in their gradual reduction to detritus is due to the 
joint action of the traffic and the weather. When the wear is con¬ 
fined to the abrasion of the surface, it is the least possible; but. 
when a road is weak from insufficient thickness, or from a yielding 
foundation, bending and cross-breaking take place under passing 
loads, and a movement is produced in the body of the road which 
causes internal wear by the rubbing of the stones against each 
other; this wear is aggravated by the softening action of water 
finding its way into the roadbed through cracks in the surface, and 
by the disintegrating action of frost; the wear and waste are thus 
far greater than on roads of sufficient strength properly maintained. 























220 


HIGHWAY CONSTRUCTION. 


410. The relative proportions in which a road is deteriorated by 
the action of atmospheric changes, wheels, and horses' feet for the 
generality of roads is approximately as follows: 


Atmospheric causes... 20 per cent 

Wheels . 35.5 “ 

Horses’ hoofs.... 44.5 “ 


411. The effect of horses’ feet is to form depressions which, if 
not immediately eradicated, prepare the way for further injury by 
the wheels. Horses moving at a walk and drawing heavily-loaded 
wagons do far more injury than horses travelling quickly and draw¬ 
ing lightly-loaded vehicles. 

412. The quantity of stone worn away annually from the sur¬ 
face of roads is an exceedingly variable quantity, dependent not 
only upon the character of the stone and the quantity of the traffic, 
but also upon the mode of maintaining the road. Mud is an ex¬ 
cellent assistant in rapidly grinding down the surface. Many 
attempts have been made to measure the wear on roads, but no 
definite conclusions can be arrived at. 

413. The wear or loss of thickness on some of the heavily trav¬ 
elled streets of London and Paris has been as much as four inches 
per annum. In Birmingham, England, the macadam streets have 
worn down six inches in one year under a traffic of 2484 vehicles in 
ten hours. 

The average loss of thickness on the European roads appears 
not to exceed one inch per year. 

414. The amount of material used annually in England to re¬ 
place the wear on main roads varies from 40 cubic yards per mile 
in the country districts to 1000, and in some cases to 1500 cubic 
yards in the vicinity of large towns. The general average appears 
to be from 70 to 80 cubic yards per mile, the least being 10 cubic 
yards per mile. 

The average annual consumption of broken stone to replace 
wear in France and Austria appears to be about 70 cubic yards per 
mile. 

415. The loss of thickness by wear should be restored annually 
by spreading coats of two or more stones thick and consolidating it 
with the roller. Before applying the coating the surface of the 
road should be broken up with picks in cross-courses about 4 inches 
apart; the depth to which the surface is broken should not exceed 









B RO K E N-STO N E PAVE M ENTS. 


221 


2 inches. Steam rollers are furnished with picks for this purpose, 
but their employment is not satisfactory or advantageous; if the 
spikes are short, they have no effect on the road unless it is soft ; if 
tfooy are long, they penetrate the body of the road, breaking the 
bond, and leave the road a mass of loose stones. Besides the employ¬ 
ment of the roller for this purpose shakes and strains it consider¬ 
ably. 

416. The practice of spreading the new coating and leaving it 
to be consolidated by the traffic is open to- the same objections as 
the construction of unrolled roads. It is an obstacle instead of an 
aid to traffic. 

When the stone is spread, the sooner it is rolled solid the better. 

417. Recoating the road should be done at that season of the 
year which will interfere the least with the movement of the traffic. 
Wet or damp weather is most suitable, but when water is obtainable 
it may be done at any season. 

418. Cost of Maintenance.—The cost of maintaining broken- 
stone pavements varies between very wide limits. A road with 
little traffic, well drained, and exposed to the sun and air, with 
fairly good materials at hand, can be kept in repair at a very small 
yearly cost, while a suburban or city street may cost several hun¬ 
dred dollars. Unless the amount of the traffic, the quantity of ma¬ 
terials used, their price, and other particulars be taken into account, 
the cost per mile or square yard at which a road is maintained 
affords little real information, and may be misleading. 

In London the cost of maintaining macadam pavements is 
stated as follows: 

Id heavy-traffic streets .. 

In moderate-traffic streets 

lu light- “ “ . 

In lightest- “ “ . 

In Paris macadam costs about 45 cents per square yard per 
year. In Boston, Mass., about 50 cents. 

The cost of maintaining the high-roads of Austria ranges from 
$1032 to $1571 per mile per annum; of these amounts about 50 per 
cent (49 to 52) is for materials. The highways of Belgium cost be¬ 
tween 6 and 10 cents per square yard per year. 


62$ cts. per sq. yd. 
29f 
1U 
61 







222 


HIGHWAY CONSTRUCTION. 


The French roads cost from 1 to 10 cents per square yard per 
year. 

The annual cost of maintaining the government roads of Bavaria 
in 1877 was, per kilometer, or .62 English mile, as follows: 


Cost of material. 

lHlvt.rfi lsihn?' .. 

. $54.26 

. 11.42 

TiriHirps qnrl pnlvprt.ft.-.. . 

. 2.52 

Retainiug-walls and gutters...... 

.31 

"R.nnH -navin cr . . 

. 2.45 

fW. nf tnnl« .. 

. 1.02 


$71.98 


or about $116.09 per English mile. Total number of men em¬ 
ployed on the government roads was 1089. The average cost of 
regular roadmen per English mile was $45.25. 

Total length of government roads: 

The total length of government roads macadamized. 4,223 miles 

“ “ “ “ “ “ paved. 29 “ 

“ “ “ “ “ “ overbridges. 6 “ 

4,258 miles 

419. Descriptions of Modern Broken-stone Roads.—“ First-class 

metropolitan roads, England: The ground is excavated or filled to 
the required level, then thoroughly consolidated by rolling. On the 
earth-bed thus prepared a bottoming or bed 12 inches thick, of 
“ hard core,” consisting of brick rubbish, clinker, old broken con¬ 
crete, broken stone or shivers, or any other hard material in pieces, 
is spread and rolled down to a thickness of 9 inches, and any loose 
or hollow places made up to the level. 

“ Next comes a layer of Thames ballast 5 inches thick, rolled 
solidly to a thickness of 3 inches. The ballast serves to fill up the 
vacancies in the bottoming, and, being less costly, saves so much 
of the cost for broken granite.” 

Broken granite, or macadam, is laid upon the prepared surface 
of the ballast in two successive layers 3 inches thick, rolled succes¬ 
sively to a combined thickness of 4 inches; a layer of sharp sand 
£ or § inch thick is scattered over the second layer, and rolled 
into it with plenty of water. 

420. The method adopted in Chicago is as follows: The roadbed 
is prepared to the required contour and well consolidated with a 















BROKEN-STONE PAVEMENTS. 


223 


steam roller. On this surface rubble-stone is carefully placed by 
hand, with its broadest side downwards, then 12 inches of broken 
stone are spread, 6 inches at a time, thoroughly rolled, to bond it; 
it is then topped with 4 inches of crushed trap or other equally hard 
rock; this is again thoroughly rolled, so as to compact and bind it 
together. 

421. The method adopted in the construction of the Bridgeport, 
Conn., roads is as follows: The ground is graded and regulated with 
a gutter 18 inches deep on each side; the soil is then thoroughly 
rolled with a 15-ton roller, and the stone spread on the surface so pre¬ 
pared. Three varieties of soil are met with in Bridgeport: (1) a fine 
“ dead ” sand, which sometimes cannot be rolled on account of its 
pushing before the roller, without covering it with coarse broken 
stone—this expedient, acting as a pavement, prevents movement; 
(2) loam, and (3) a hard-pan with mica disseminated through 
it. Underdraining has in no case been resorted to, the 18- 
inch gutters being depended on for drainage. After the broken 
trap-rock is rolled to a bearing, screenings are added as a binder 
and the road metal is well and thoroughly filled with them, the 
whole being rolled until the water flushes on the surface. A strong 
silicious sand is sometimes used, in part, in place of screenings, and 
when, in dry weather, the road commences to break up or “ ravel/’ 
out of easy access by watering-carts, sand is spread over the sj)ot, 
which quickly consolidates the road. No loam or clay is used as a 
binder or filler in the construction of the roads, nor in their repair, 
except when the surface over a ditch is to be replaced and it is too 
small a patch to justify bringing the roller; then the broken trap 
is laid down after being mixed with the proper quantity of screen¬ 
ings, and the whole covered with loam. The traffic consolidates it 
in a short time. 

It should be noticed, in connection with the low cost of those 
roads stated in Table XLII,—about 28 cents per square yard,—that 
Bridgeport, in addition to the possession of particularly good trap- 
rock, is exceptionally favored in the location of its quarry almost 
exactly two miles from the centre of the city; so that the cosi of 
the stone is 82 cents per gross ton of 21 or 22 cubic feet, delivered 
to the wagons ; and the cost of hauling varies, depending on the 
distance, from 50 to 75 cents per ton, or between $1.32 and $1.57 
per gross ton delivered on the road. The trap-rock is broken to 2- 




224 


HIGHWAY CONSTRUCTION. 


inch size by three 7 X 10-inch Marsden crushers, placed side by side 
on a platform, to which cars are drawn from the quarry by a wire 
rope, wound by the same engine which runs the crushers. The in¬ 
terest on the cost of the roller—an Aveling & Porter, now twenty 
years old—is not reckoned in the above-mentioned cost. 

That the cost of the Bridgeport roads has not been underesti¬ 
mated is apparently made certain by the contract price of such 
work in the neighboring town of Fairfield, where, with a longer 
haul, a 4-inch road 20 feet wide was built for 85 cents per lineal 
foot or 38.3 cents per square foot. This sum included regulating, 
some grading, and the use of a roller, as well as the contractor’s 
profit. 

422. Extracts from Specifications for forming Telford Roads in 
St. Louis, Mo. 

Drainage .—All drains considered necessary by the Street Com¬ 
missioner to carry off the water shall, when required, be made by 
the contractor for the work, and shall be paid for at a price agreed 
upon by the Street Commissioner. 

Sub-foundation .—After the curbstones are set, the second grad¬ 
ing and shaping of the roadway shall be done. All surplus earth 
and other material shall be removed and the sub-foundation formed 
to a depth of eighteen (18) inches below the intended surface of the 
street, the cross-section thereof to conform in every respect to the 
cross-section of the pavement when finished. The roadbed shall 
then be rolled with a roller weighing not less than five (5) tons, 
when required by the Street Commissioner. All depressions which 
may appear shall be carefully refilled before any stone is put on. 

Lower Course of Telford .—When the street shall be thus graded 
and formed, a bottom course or layer of limestone of approved 
quality shall be laid by hand in regular straight courses at right 
angles with the line of the streets, so as to break joints; the bot¬ 
tom surfaces of the stones shall form as close joints as possible. 
The stones to be used shall not be less than three (3) inches nor 
more than eight (8) inches thick, and from five (5) to ten (10) 
inches long on their bottom surfaces, and must be thoroughly set¬ 
tled to place with hammers. The interstices shall then be llied 
with stone chips firmly wedged by hand with hammers, and all 
projecting points shall be broken off. The tops of the stones when 
levelled off shall have a surface not greater than one third of the. 




BROKEN-STONE PAVEMENTS. 


225 


base. The foundation or bottom course when finished shall have 
a regular and uniform depth of not less than seven (7) inches. 
The bottom course along the curb and under the gutter for a width 
of four (4) feet, and under the cross-walk for a width of eight (8) 
feet, shall be thoroughly consolidated by rolling or ramming, and 
the surface be made even by filling the spaces between the stones 
with sand in such manner as the Street Commissioner may direct. 

Guttering .—After the Telford foundation has been prepared 
the gutter shall be put down upon a bed of clean coarse sand at 
least two (2) inches deep. The paving-blocks shall be from six (G) 
to seven (7) inches deep, four (4) to six (G) inches thick, and eight 
(8) to twelve (12) inches long. The faces shall be straight, free 
from bunches, depressions, and inequalities exceeding one half (£) 
inch. The faces shall meet at right angles, and the corresponding 
dimensions of opposite faces shall not vary more than one-half (|) 
inch. They must be set vertically on edge, in close contact with 
each other, in straight rows at right angles with the curb, the 
blocks in different rows breaking joint by a space not less than 
four (4) inches. The joints between the blocks shall be filled with 
clean, sharp sand. 

Cross-gutters .—The cross-gutters shall be of such width and 
shape as may be directed. The stone used therefor shall be from 
three (3) to six (6) inches thick, nine (9) inches deep, and from 
six (6) to twelve (12) inches long. The bottom course of stone 
shall be eight (8) inches thick, nine (9) inches deep, and not less 
than twelve (12) inches long. 

Quality and Finish of Stone Work .—All stones used for 
gutters, cross-gutters, and cross-walks shall be limestone of the best 
quality, from ledges known to withstand the effects of frost, and 
free from seams and all other defects. All paving-stone shall be 
dressed so as to make close joints at least four (4) inches deep, and 
have a square bottom not less than three quarters (f) of the super¬ 
ficial surface of the top of the same stone. All materials shall be 
fully dressed before they are brought onto the street to be im¬ 
proved. The whole paving must be made tight, compact and 
smooth, and be fully fed with sand, and must be laid true and uni¬ 
form, with broken joints, and have a full bond of at least four (4 )\ 
inches. After the paving is laid it must be sanded on top, the* sand 



HIGHWAY CONSTRUCTION”. 


/JrJVJ 


TYPE-SECTIONS OF BKOKEN-STONE PAVEMENTS. 



Fig. 25. COUNTRY ROAD, SIDE-DITCH FILLED WITH 

COBBLE. 



Fig. 26. COUNTRY ROAD, WITH EARTH BERM AND 

TILE-DRAIN. 




Fig. 28. CITY STREET, WITH STONE-BLOCK GUTTER. 
































































BROKEN-STONE PAVEMENTS. 


227 


swept into the joints with a broom, and be settled down evenly and 
firmly with a rammer of not less than forty (40) pounds weight. 

Macadam or Second Course .—When the Telford foundation has 
thus been formed, there shall be placed thereon a layer of clean, 
hard limestone macadam, free from clay, earth, rubbish, or other 
foreign matter, so broken that the largest pieces shall pass through 
a two and one half (24) inch ring in all their dimensions, and shall 
be fully broken before it is brought on the line of work. This 
course shall have such a depth and form of cross-section as may be 
directed by the Street Commissioner, and shall be thoroughly con¬ 
solidated by rolling with a roller weighing not less than five (5) tons. 

Sand .—The macadam course having been finished, the spaces 
between the stones shall be well filled with clean, coarse sand, or 
so much sand as may be directed by the Street Commissioner, which 
shall be washed in with water from a hose having a rose attached 
to the nozzle, and then the whole shall be rerolled to the satisfac¬ 
tion of the Street Commissioner. A sprinkling-cart shall not be 
used unless it is impossible to make a connection with a fire-plug, 
and then only with the consent of the Street Commissioner. A 
water license and a permit from the Water Commissioner must 
first be obtained before a fire-plug can be opened. 

Gravel .—The macadam course with binding material having 
been finished, there shall be placed thereon a layer of good clean 
gravel, free from clay, animal, or vegetable matter, and containing 
not more than fifteen (15) per cent of loam or sand, nor shall the 
largest pebbles exceed one inch in diameter; to be well wetted down 
or slushed with water and thoroughly rolled to a perfect surface, 
having such form of cross-section aud depth as may be directed by 
the Street Commissioner. 

423. Heads of Specifications for Broken-stone Pavements. 

(1) Preparation of roadbed. 

(2) Foundation (sand, gravel, etc.). 

(3) Quality of the stone. 

(4) Size of the stone. 

(5) Cleanness of the stone. (The stone must at all times be 
clean and free from clay or other dirt.) 

(6) Spreading the stone. 

(7) Thickness of layers. 

(8) Polling: weight of roller and amount of rolling. 



228 


HIGHWAY CONSTRUCTION - . 


(9) Watering. 

(10) Binding, quality and quantity of. 

(11) Interpretation of specifications.- 

(12) Omissions in specifications. 

(13) Engineer defined. 

(14) Contractor defined. 

(15) Notice to contractors, how served. 

(16) Preservation of engineer’s marks, etc, 

(17) Dismissal of incompetent persons. 

(18) Quality of materials. 

(19) Samples. 

(20) Inspectors. 

(21) Defective work, responsibility for. 

(22) Measurements. 

(23) Partial payments. 

(24) Commencement of work. 

(25) Time of completion. 

(26) Forfeiture of contract. 

(27) Damages for non-completion. 

(28) Evidence of the payment of claims. 

(29) Protection of persons and property. 

(30) Indemnity bond. 

(31) Bond for faithful performance of work. 

(32) Power to suspend work. 

(33) Right to construct sewers, etc. 

(34) Loss and damage. 

(35) Old materials, disposal of. 

(36) Cleaning up. 

(37) Personal attention of contractor. 

(38) Payment of workmen. 

(39) Prices. 

(40) Security retained for repairs. 

(41) Payment, when made. Final accejitance. 



CHAPTER VIII. 


MISCELLANEOUS PAVEMENTS. 

424. Gravel Roads. —Gravel, though not as durable as broken 
stone, has proved very serviceable as a road covering. 

In selecting gravel for this purpose, the chief quality to be 
sought for is the property of binding. The binding properties are 
two: the presence of ferruginous clay, which causes the gravel to 
set or become hard as soon as it is exposed to the action of the 
atmosphere; and the angular shapes and sizes of the stones. 

425. Gravel from the sea-beach and shores of rivers, and that 
in which the stones are round or oval, with regular smooth sur¬ 
faces, never forms a good binding material, even if mixed with 
ferruginous clay. The reason is that the stones which are on the 
surface have no mechanical hold on those which are beneath or be¬ 
side them, but being merely cemented by means of the clay they 
are easily loosened and thrown out of place by the action of the 
traffic or frost, and even by the alternate actions of drought and 
moisture. 

426. When no gravel but that found in rivers or on the sea-shore 
can be obtained, one-half of the stones should be broken and mixed 
with the other half; to the stone so mixed a small quantity of clay 
or loam, about one-eighth of the bulk of the gravel, must be added: 
an excess is injurious. Sand is unsuitable: it prevents packing in 
jn’oportion to the amount added. 

427. Preparing the Gravel. —Pit-gravel usually contains too 
much earth, and should be screened before being used. Two sieves 
should be provided,—one with meshes of one and one-half inches, 
so that all pebbles above that size may be rejected, the other with 
meshes of three quarters of an inch, and the material which passes 
through it should be thrown away. The expense of screening will 

be more than repaid by the superior condition of the road formed 

229 


230 


HIGHWAY CONSTRUCTION. 


by the cleaned material, and the diminution of labor in keeping it 
in order. The pebbles larger than one and a half inches may be 
broken to that size and mixed with the cleaned material. 

428. Laying the Gravel. —On the roadbed properly prepared 
a layer of the prepared gravel four inches thick is uniformly spread 
over the whole width, then compacted with a roller weighing not 
less than two tons, and having a length of not less than thirty 
inches. The rolling must be continued until the pebbles ceases to 
rise or creep in front of the roller. The surface must be moistened 
by sprinkling in advance of the roller, but too much water must 
not be used. Successive layers follow, each being treated in the 
above-described manner until the requisite depth and form has 
been attained. 

429. The gravel in the bottom layer must be no larger than 
that in the top layer; it must be uniformly mixed, large and small 
together, for if not so the vibration of the traffic and the action of 
frost will cause the larger pebbles to rise to the surface and the 
smaller ones to descend, like the materials in a shaken sieve, and 
the road will never be smooth or firm. 

The pebbles in a gravel road are simply imbedded in a paste 
and can be easily displaced. It is for this reason, among others, that 
such roads are subject to internal destruction. 

430. The binding power of clay depends in a large measure 
upon the state of the weather. During rainy periods a gravel road 
becomes soft and muddy, while in very dry weather the clay will 
contract and crack, thus releasing the pebbles, and giving a loose 
surface. The most favorable conditions are obtained in moderately 
damp or dry weather, during which a gravel road offers several 
advantages for light traffic, the character of the drainage, etc., 
largely determining durability, cost, maintenance, etc. 

431. Repair. —Gravel roads constructed as above described will 
need but little repairs for some years, but daily attention is required 
to make these. A garden rake should be kept at hand to draw any 
loose gravel into the wheel-tracks, and for filling any depressions 
that may occur. 

In making repairs, it is best to apply a small quantity of gravel 
at a time, unless it is a spot which has actually cut through. Two 
inches of gravel at once is more profitable than a larger amount. 
Where thick coating is applied at once it does not all pack, and if, 




MISCELLANEOUS PAVEMENTS. 


OQ t 

/wU L. 


after the surface is solid, a cut be made, loose gravel will be found; 
this holds water and makes the road heave and become spouty under 
the action of frost. It will cost no more to apply six inches of 
gravel at three different times than to do it all at once. 

At every one-eighth of a mile a few cubic yards of gravel should 
be stored, to be used in filling depressions and ruts as fast as they 
appear, and there should be at least one laborer to every five miles 
of road. 

432. Cost of Construction in Illinois. —The cost has been about 
$900 per mile for a roadway 12 feet wide, 12 inches deep at the 
centre and 9 inches at the sides. 

Table XLIII shows the extent and cost of gravel pavements in 
some of the principal cities in the United States. 


TABLE XLIII. 

Extent and Cost of Gravel Pavements in some of the Principal 

Cities of the United States. 


Cities. 

Extent. 

Miles. 

Cost of Construction 
per square yard. 

Tension IVTass . .. 

160.00 

$0.75 

ClnmhriHcrp MflSS. 

67.91 

TU'phmnnrl Vft.. 

46.44 

$0.15 to $0.20 

Wfl<ihin crtnr) L) C. 

33.50 

ftranrl H.rnrirls TVliutl. . • , 

32.37 


Ttnrl i n crtnn V t. . 

11.92 


TTm vprhill Mass .... 


$0.25 




433. Weight of Gravel. —A cubic yard of pit gravel weighs 
about 3300 pounds. When the distance is not greater than U 
miles, a team will haul about 7 cubic yards a day; even with hauls 
of six miles the work can be done at reasonable cost. 

434. Bituminous Macadam.-— In some towns in England bitu¬ 
minous or asphalt macadamized roadways are made. This consists 
in mixing ordinary coal-tar with the road metal ordinarily employed 
for macadamized roads; only it must be borne in mind that the 
metal employed must be limestone or some other soft material, 
otherwise it will not wear down evenly with the tar, and thus a 
lumpy surface will be produced in course of time. 

The method of mixing is by heating the stone, which has of 
course been previously broken to the required size, and then thor- 

























232 


HIGHWAY CONSTRUCTION. 


oughly mixing and incorporating it with the tar. This is carried 
to the roadway, is spread in the ordinary manner, and well rolled 
to the proper contour, a surface being afterwards given to it by a 
coating of about 2 inches thick, composed of a similar mixture, the 
stones of which are of much smaller size. 

Another method is to place about 6 inches of the broken stone 
upon the necessary foundation. Upon this a boiling mixture, com¬ 
posed of about 50 gallons of creosote oil and 1 ton of pitch, is 
poured until every interstice is filled with the mixture. Whilst 
this is still warm, a thin layer of small broken stone is spread upon 
the surface and well rolled; more small stones or chippings are 
added, and the whole is rolled until the surface of the roadway has 
attained its proper contour and presents a perfectly smooth and 
clean appearance, little inferior to that of real asphalt. 

Dry weather is essential whilst this class of roadway is in course 
of construction, and careful watching is required, as when the skin 
breaks the whole roadway soon disintegrates. This class of pave¬ 
ment has, however, many advantages over ordinary macadamized 
roadways when finished, not the least of them being impervious¬ 
ness to moisture, and the ease with which it may be cleaned. 

435. In repairing some of the macadam roads and pavements in 
Paris, fragments of old asphalt were mixed with the broken stone. 
The results, as regards wearing qualities, show little improvement 
over the unmixed stone, but such a pavement keeps remarkably 
clean during dry weather and does not become as muddy as the true 
macadam during rainy seasons. 

In the middle of summer an unpleasant odor is given out, and 
the surface has a dirty black color. 

436. Concrete Macadam, introduced by Mr. J. Mitchell, London 
Eng., is composed of broken stone, sand, and Portland cement so 
proportioned that the spaces, otherwise vacant, and ultimately filled 
with muddy cementing matter of worn macadam, are filled with an 
admixture of Portland cement or other hydraulic cement-grout. 
The concrete thus formed rapidly becomes a uniform and impervious 
mass which is wholly unaffected by heat or moisture. It is mixed 
in these proportions: 

Broken stones. 4 measures 

Clean, sharp sand. l£ to 1£ “ 

Portland cement..1 “ 






MISCELLANEOUS PAVEMENTS. 


233 


So for a cubic yard, or 27 cubic feet, of broken metal 6f cubic 
feet, or 1 £ barrels (of 44 cubic feet), of Portland cement are re¬ 
quired. The broken stone should be of the hardest quality, of 
uniform size, thoroughly screened; and it should be thoroughly 
wetted before being incorporated with the cement. 

Cement of the best quality must be employed, and the sand 
should be sharp, clean, and gritty. The surface of the ground is 
brought to form, and rolled several times. The concrete is then 
laid on the surface in a layer 3 or 4 inches, and is left for three 
days to harden. The second layer of 3 or 4 inches is next laid on 
the first, and immediately rolled to form with a heavy iron roller, 
as heavy as two or three men can draw. The cement should be left 
for three weeks, to allow it to become quite hard before the road is 
opened for traffic, although a week has been found to be a sufficient 
interval. 

Mr. Mitchell states that a concrete road, 7 inches deep at the 
middle and 5 inches at the sides, is sufficient for ordinary traffic. 
Por heavy traffic a depth of 8 inches is recommended. 

The first piece of concrete road was laid in 1865 in Inverness, 
and consisted of 45 lineal yards of the approach to the freight sta¬ 
tion of the railway. In 1870, after the road had been under traffic 
for 4£ years, it was reported that the wear of the surface was scarcely 
appreciable, whilst the adjoining macadamized road had been coated 
frequently every year. 

Another specimen, 50 yards long and 15 yards wide, was laid in 
1866, on George IV. Bridge, Edinburgh, where the traffic is heavy 
and continuous. At the end of three years and a half under traffic 
the surface was perfectly sound and immovable. 

The amount of vertical wear during the periods above named 
appears not to have exceeded £ inch. But- Mr. J. H. Cunningham, 
writing in January, 1875, stated that it was then much worn at the 
surface, in consequence, he thought, of its great hardness and 
rigidity. 

437. Stone Trackways (Figs. 29 to 32).—Trackways formed of 
stone slabs were first employed by the Egyptians for moving great 
weights. In modern times they reappeared in northern Italy, where 
they are in general use not only in the streets of the principal cities, 
but also in the smaller towns. 

Telford employed a stone trackway on the Holyhead Road to 



234 HIGHWAY CONSTRUCTION. 

*• 



Fig. 29 —SECTION OF STONE TRACKWAY. 



Fig. 30.-PLAN OF TRACKWAY. 



Fig. 31.—PLAN OF CROSSING. 





























































MISCELLANEOUS PAVEMENTS 


235 



Fig. 32 .—Junction of Curves with Straight Line 












































































































































































































































236 


HIGHWAY CONSTRUCTION. 


avoid excessive work of construction. There were two hills each a 
mile in length, with an inclination of 5 : 100. To reduce this to a 
4-i- per cent grade would have cost $100,000, but nearly the same 
advantage in diminishing the amount of tractive force required was 
obtained by making stone trackways at a total expense of one half 
the former amount and retaining the 5 per cent grade with moderate 
cutting and embankment. To draw one ton over the original 
hills required a tractive force of 294 pounds; to draw the same load 
over the trackways laid on the same inclinations required only 132 
pounds. 

Trackways of both stone and iron have been used in London, 
Liverpool, Manchester, Glasgow, and other cities. 

438. The Italian trackways consist of two parallel lines of granite 
blocks, usually 14 inches wide, 8 inches deep, and 5 feet in length, 
bedded in a layer of sand. The lines are 28 inches apart, and the in¬ 
terspace, or footway for horses, as well as the other portions of the 
roadway, is paved with cobbles obtained from the Po, or from other 
rivers. These stones should be egg-shaped, with a maximum diame¬ 
ter of from 34 to 4| inches and a depth of from 4| to 5J inches. 
The roadway is usually formed with a slight inclination downwards 
towards the centre. By this arrangement the space between the 
trams serves as a channel to receive the surface-water, and is provided 
with stone gratings, placed at suitable intervals, by which the water 
escapes into the sewers. The surfaces of the trams are slightly in¬ 
clined towards each other, the inner edges being f inch lower than 
the outer edges; whilst the interspace is concave, having a versed sine 
or depression of 14 inches. The foundation of the roadw r ay consists 
of a layer of screened gravel, about 6 inches deep, watered so as to 
form a compact mass. Two inches of sand is laid on the gravel, as 
a bed for the paving-stones. The upper surfaces of the trams are 
dressed flat and the ends square, to form close joints. The stone 
gratings for the gulleys are 32 inches long, formed with three slots 
12 inches long and 14 inches wide. After the trams are placed, the 
other portions of the pavement are completed. After the surface 
has been well rammed with a wooden rammer, it is watered and 
covered with a bedding of sand f inch deep, so as to fill the joints 
by degrees. On steep gradients the surfaces of the trams are 
grooved diagonally. 

439. Trackways are expensive to construct (cost about $14,000 



MISCELLANEOUS PAVEMENTS. 


237 


per mile for two lines of track and intermediate paving in the 
neighborhood of New York), but cost little for repairs and mainte¬ 
nance. Their advantages are many: they combine the opposite 
qualities required for easy haulage, viz., a smooth surface for the 
wheels, on which the friction is reduced to the least possible amount, 
and a rough footway, affording a firm foothold for horses, thus 
enabling them to exert their utmost tractive power. For this reason 
they ought to receive more attention than is now accorded them. 
The friction of their surface is only about of the load, or about 
one half that of the best block pavement. It is stated that on such 
trackways in London a horse weighing about 700 pounds could 
draw on a level 15 tons, and a horse weighing about 1600 pounds 
could draw 30 \ tons. 

440. In Glasgow, Scotland, there was a trackway down for forty 
years. It consisted of cast-iron plates 2 inches thick, 8 inches 
wide, and cast in lengths of 3 feet. It was laid in Buchanan Street 
on a 5 per cent grade. 

441. The trackways for the wheels may be of granite, or 
compact sandstone slabs 12 to 24 inches wide, 6 inches thick, 
and in lengths of 2 to 6 feet. The footway for the horses to be in 
all cases paved with cobblestones the other portions of the road¬ 
way may be paved with cobblestones, granite, or other pavement. 

The foundation for the trackways should be constructed as shown 
in Fig. 29, with all the joints filled with asphaltic paving-cement. 

The roadway may be formed in the usual manner with the 
trackways level (transversely), the surface falling from their outer 
edge to the gutters; but at frequent intervals in the horse-path 
catch-basins with iron or stone covers should be placed, connecting 
with the sewer. At track-crossings or junctions the surface of the 
slabs should be grooved, so as to afford good foothold for the horses 
passing over them. 

442. “ Jasperite.”—Jasperite, under what is known as “ Drake’s 
Patent,” consists of quartzite crushed to sizes of J, J-, and } of an 
inch, and known as Nos. 3, 4, and 5, respectively. The foundation 
is composed of irregularly broken stone set to form a rough pave¬ 
ment similar to that used for a Telford road. On this is spread a 
layer of concrete l\ inches thick, composed as follows: 1 part of 
Portland cement, 1 part of sand, and 3 parts of quartzite of the 
sizes Nos. 3 and 4. This is well mixed, spread, and rammed into 





238 


HIGHWAY CONSTRUCTION. 


place in such a manner as to form blocks one yard square. These 
blocks are separated by tarred paper. On the bed so formed is 
spread a layer one-half inch in thickness, prepared in the same way, 
but substituting quartzite of the size known as No. 5. This pave¬ 
ment is in use in Sioux Falls, S. D., and Wichita, Kan. The cost 
per square yard is about $2.50, with a five-year guarantee. 

443. Artificial Granite Blocks are formed from the chippings of 
granite quarries. It is mixed at the place where it is to be used 
with Portland cement in sufficient quantity to make a thorough 
bond between the pieces, and put down in blocks or squares so as 
to form separate stones as it were. Its surface is kept compara¬ 
tively rough by the cement wearing below the points of the granite. 
Its advantage is, presumably, cheapness. 

444. Plank Roads.—In localities where timber is abundant and 
other materials are unobtainable, planks may be employed to form 
pavements. When new and well laid they form a comfortable car¬ 
riageway both for haulage and pleasure, but make when worn and 
displaced a very disagreeable road. 

445. The method most generally adopted in constructing plank 
roads consists in laying a flooring or track 8 feet wide, composed of 
boards from 9 to 12 inches in width and 3 inches in thickness, 
which rest upon two parallel rows of stringers or sills laid length¬ 
wise in the road and having their centre lines about 4 feet apart or 
2 feet from the axis of the road. Sills of various-sized scantling 
have been used, but experience seems in favor of scantling about 
12 inches in width, 4 inches in thickness, and in lengths of not 
less than 15 to 20 feet. Sills of these dimensions laid flatwise and 
firmly embedded present a firm and uniform bearing to the boards 
and distribute the. pressure they receive over so great a surface that, 
if the soil upon which they rest is compact and is kept well drained, 
there can be but little settling and displacement of the road-surface 
from the usual loads passing over it. The better to secure this uni¬ 
form distribution of the pressure, the sills of one row are so laid as 
to break joints with the other, and to prevent the ends of the sills 
from yielding the usual precaution is taken to place short sills at 
the joints, either beneath the main sills or on the same level with 
them. 

The boards are laid perpendicular to the axis of the road, ex¬ 
perience having shown that this position is more favorable to their 



MISCELLANEOUS PAVEMENTS. 


239 


wear and tear than any other, and is besides the most economical. 
Their ends are not in an unbroken line, but so arranged that the 
ends of every three or four project alternately, on each side of the 
axis of the road, 3 or 4 inches beyond those next to them, for the 
purpose of presenting a short shoulder to the wheels of vehicles to 
facilitate their coming upon the plank surface when from any cause 
they may have turned aside. On some roads the boards have been 
spiked to the sills, but this is unnecessary, the stability of the 
boards being best secured by well packing the earth between and 
around the sills, so as to present a uniform bearing surface to the 
boards, and by adopting the usual precautions for keeping the sub¬ 
soil well drained and preventing any accumulation of rain-water 
on the surface. The boards for plank roads should be selected from 
timber free from the usual defects, such as knots and shakes, which 
would render it unsuitable for ordinary purposes, as durability is an 
essential element in the economy of this class of road-construction. 
Boards of 3 inches in thickness offer all the requisites of strength 
and durability that can be obtained from timber in its ordinary state, 
in which it is used for plank roads. 

Besides the wooden track of 8 feet, an earthen track of 12 feet 
in width is made, which serves as a summer road for light vehicles 
and as a turnout for loaded ones. This, with the wooden track, 
gives a clear road-surface of 20 feet, the least that can be well 
allowed for a frequented road. It is recommended to lay the 
wooden track on the right-hand side of the approach of a road to a 
town or village, for the proper convenience of the rural traffic, as 
the heavy trade is to the town. The surface of this track receives 
a cross-slope from the side towards the axis of the road outwards of 
1 in 32. The surface of the summer road receives a cross-slope in 
the opposite direction of 1 in 16. These slopes are given for the 
purpose of facilitating a rapid surface for draining. The side 
drains are placed for this purpose parallel to the axis of the road 
and connected with the surface in a suitable slope. 

Where from the character of the soil good summer roads cannot 
be had, it would be necessary to make wooden turnouts from space 
to space, to prevent the inconvenience and delay of miry roads. 
This can be effected by laying at these points a wooden track of 
double width, to enable vehicles meeting to pass each other. It is 
recommended to lay these turnouts on four or five sills, to spring 



240 


HIGHWAY CONSTRUCTION. 


the boards slightly at the centre, and spike their ends to the ex¬ 
terior sills. 

In some of the earlier plank roads a width of 16 feet was given 
to the wooden track, the boards of which were laid upon four or 
five rows of sills. But experience soon demonstrated that this was 
not an economical plan, as it was found that vehicles kept the 
centre of the wooden surface, which was soon worn into a beaten 
track, whilst the remainder was only slightly impaired. This led 
to the abandonment of the wide track for the one now usually em¬ 
ployed, which answers all the purposes of the traffic and is much 
more economical, both in the first outlay and for subsequent re¬ 
newals and repairs. Plank roads possess great advantages in a 
densely-wooded country, and will be found superior to every other 
kind as a temporary expedient. 

446. The cost per mile ranges from $1000 to $4000, and the life 
is about eight years. 

447. Log Roads.—When a road passes over soft swampy ground, 
always kept moist by springs which cannot be drained without too 
much expense, and which is surrounded by a forest, it may be 
cheaply and rapidly made passable by felling a sufficient number 
of young trees, as straight and as uniform as possible, and laying 
them side by side across the road at right angles to its length. 
This arrangement is well known under the term “corduroy road.” 
Though its successive hills and hollows otfer great resistance to 
draught and are very unpleasant to persons riding over it, it is 
nevertheless a very valuable substitute for a swamp, which in its 
natural state would at times be utterly impassable. 

448. Charcoal.—In some of the Western States, where wood is 
abundant and cheap, roads covered with charcoal have been made 
as follows: Logs from six inches to two feet in diameter and from 
twelve to twenty-four feet long are cut and piled lengthwise along 
the road about six feet high, being nine feet on the bottom and 
two on top, and then covered with straw and earth, or simply with 
sods, and burned in the manner of coal-pits. The covering is 
taken from the sides of the road, and the ditches thus formed 
afford good drainage. After the timber is converted into charcoal, 
the earth is removed to the side of the ditches, the coal raked 
down to a width of fifteen feet, leaving it two feet thick at the cen¬ 
ter and one at the sides, and the road is completed. 




MISCELLANEOUS PAVEMENTS. 


241 


449. A road thus made in Michigan cost $660 per mile, and is 
said to be very compact and free from mud or dust. At a season 
when the mud on the adjoining earth road was half-axletree deep, 
on the coal road there was not the least standing, and the impress 
of the feet of a horse passing rapidly over it was like that made on 
hard-washed sand, as the surf recedes, on the shore of the lake. 
The water was not drained from the ditches, and yet there were no 
ruts or inequalities in the surface of the coal road, except what was 
produced by more compact packing on the line of travel. It is 
probable that coal will fully compensate for the deficiency of lime¬ 
stone and gravel in many sections of the West, and, where a road is 
to be constructed through forest land, that coal may be used at a 
fourth the expense of limestone. 

450. Iron.—Iron is eminently durable, but as a pavement it is 
a failure. It is so slippery even when roughened that horses can¬ 
not gain a foothold on it. About thirty years ago Oortlandt Street 
in New York was paved with it. In order to guard against slipper¬ 
iness the surface was made rough and consisted of hexagonal prp- 
jections about an inch in size, separated by depressions of about 
the same size. It was both rough and noisy; the horses caught 
their calks in the depressions and twisted off their shoes, and in 
spite of its roughness the horses fell frequently and with disastrous 
results in tearing their knees on the sharp projections. It remained 
in use but a short time and was replaced with stone. Combinations 
of wood and iron, concrete and iron, are frequently introduced and 
experimented with, but so far none have been a practical success. 

450a. Furnace Slag.—Slag and cinders from iron and copper 
works may be employed with advantage when they are procurable, 
and when no stone sufficiently tough to withstand the action of 
heavy traffic can be obtained. They are both very durable, but 
care is required in the selection of the tougher sorts. They have 
no binding properties, and on this account are sometimes used with 
limestone; a rough surface will, however, always result from the 
unequal wear of two materials so different in hardness. Limestone 
scrapings, coal ashes or clay, laid on as a binding material, aid con¬ 
solidation very much, and also prevent injury to horses' feet from 
the sharp edges of the fresh-laid slag. 

450b. Blocks formed by casting furnace slag in moulds are in use 
in England and other parts of Europe. Their quality varies with 



242 


HIGHWAY CONSTRUCTION. 


the amount of silica contained : if this be about 35 per cent, the 
resulting blocks are tough; hut if below 30 per cent, the block is 
brittle and easily broken. The process employed in England for the 
manufacture of these blocks, and which seems to produce a tough 
and durable article, is to run the slag from the furnace into a ladle, 
then pour it from this into iron moulds of the desired shape and size 
contained on an iron plate arranged to revolve; contact with the 
moulds chills the outside of the slag block immediately, and as the 
plate makes a half revolution the bottom of the mould is opened 
by mechanical means and the chilled block dropped either on a bed 
of sand or a conveyor. From here, and while the interior of the 
block is still in a molten condition, it is placed in an annealing oven, 
which, when fully charged, is sealed and allowed to cool, no heat 
being used other than that furnished by the blocks themselves. 

450c. Chert.—This material is employed for street and road 
paving in some of the Southern States, notably Alabama, where it is 
found in inexhaustible quantities overlying the red sandstone, which 
forms the covering of the red hematite iron ore, and underlying the 
sub-carboniferous limestone. The cities of Montgomery and Bir¬ 
mingham, Ala., and Macon and Savannah, Ga., have several miles 
of streets paved with it. There is also in both States several miles 
of country roads covered with it. 

Chert is a valuable substitute for broken stone, especially where 
stone is scarce or of unsuitable character; it furnishes an excellent 
surface and wears well under traffic with but little dust or mud. 

The material is usually laid upon a foundation of furnace slag or 
other convenient material, but in the absence of such it is laid di¬ 
rectly upon the earth surface. The thickness employed varies from 
3 to 5 inches. It is simply spread, sprinkled, and rolled. In Bir¬ 
mingham, Ala., the cost of the chert is 80 cents per cubic yard on 
the street, and the cost of the furnace slag, including hauling, 
spreading, and rolling, is from 30 to 40 cents per cubic yard. 

The name “chert” is also applied to the slag derived from the 
blast furnaces in Alabama. This material is also employed for 
street and road paving. 

450d. Florida Clay.—This name is given to a sandstone rock de¬ 
posit found in Florida, the material from which has been extensively 
used in several towns of Florida for street and sidewalk paving. Its 
use has been the means of converting streets so sandy that travel 




MISCELLANEOUS PAVEMENTS. 


243 


over them was very slow and difficult into driveways over which 
travel is easy and pleasant. 

The composition of this “clay ” is as follows : 

Moisture. 4.20 per cent. 

Silica. 69.03 “ “ 

Aluminum silicate. 18.21 “ “ 

Iron oxide . 8.53 “ “ 

Calcium carbonate. trace. 

The most valuable constituent of this material, when used as a 
covering for roads, is, no doubt, the oxide of iron, which acts as a ce¬ 
ment, rendering the material capable of becoming compact and hard. 

For use the material is q'uarried and without any preparation is 
spread over the roadway to the depth of several inches, then 
sprinkled with water and compacted with a roller. It is of a red¬ 
dish color, due to the presence of the oxide of iron. After being 
travelled over for a short time it becomes very compact and nearly 
as hard as it was in its native bed. 

450e. Tar-macadam.—A paving composition called “tar-mac¬ 
adam” has been introduced in England; it consists of granite, 
coal-tar, refined asphaltum, and creosote oil in the proportions of 
1 ton of granite broken into 1-J-inch fragments, 12 gallons of 
coal-tar, 28 pounds of asphaltum, and 2 gallons of creosote oil; 
the ingredients are heated and thoroughly incorporated. The 
pavement is formed as follows : The foundation is composed of a 
layer of hard clinkers and broken stone, 10 inches in thickness, well 
consolidated by rolling with a 12-ton steam-roller; this is covered 
with a layer 4 inches thick of stone broken into 24-inch fragments. 
This is also compacted by rolling; upon this is spread a 3-inch 
layer of the “tar-macadam”; this is thoroughly compacted by rolling 
and then covered with a 1-inch layer of limestone screenings mixed 
with the same cementing materials that are used in the macadam. 
This last layer is sprinkled with clean dry limestone screenings 
and rolled. The work should only be done in dry weather; the 
rolling should average 10 hours for each 100 square yards, and the 
traffic should not be admitted until at least 24 hours after the work 
is completed. The cost is from 84 cents to $1.00 per square yard. 

450f. Artificial Stone.—Pavements formed of artificial stone or 
concretes composed of hydraulic cement, crushed stone, sand, and 
gravel, with sometimes the addition of some indurating mineral 
substance, as baryta, litharge, etc., have been tried; they are usually 
manufactured under a patent, either in place or in the form of 








244 


HIGHWAY CONSTRUCTION. 


blocks at a factory. While artificial stone is eminently suitable as 
a paving material for footwalks, it quickly fails under the action 
of horses’ hoofs and wheels when used as a carriageway pavement. 

450g. Hydraulic cement concrete is used in several cities as a pav¬ 
ing material foralleys and is found very suitable; the following speci¬ 
fications show how these pavements are formed (see also Art. 78G): 

Specifications for Hydraulic Cement Pavement.—The material 
shall be excavated from the entire area proposed to be paved to a 
depth of eighteen (18) inches below the surface of the finished 
pavement; the excavation thus formed shall be filled to a depth of 
fourteen (14) inches with clean steam ashes or cinders, and these 
shall be thoroughly compacted by ramming. Upon the foundation 
so formed shall be laid a concrete composed of 1 part of Portland 
cement (either of Hilton or Manheimer brand) and 3 parts of 
clean, sharp, coarse sand, thoroughly mixed dry and made into 
mortar with the least quantity of water, and thoroughly intermixed 
with broken stone or furnace slag in such quantity (about 7 parts) 
that, when tamped or rammed solidly in place, free mortar will 
rise to the surface and exhibit a depth of three (3) inches of the 
said concrete. Upon this concrete foundation a surface mixture 
shall be laid one (1) inch in thickness, composed of 1 part of 
Portland cement (Dyckerhoff or Star Stettin brand) and 2 parts 
of crushed granite, with just sufficient water to make a stiff mor¬ 
tar; this surface coat shall be thoroughly compacted by tamping; 
and shall be dressed with a small quantity of dryer, composed of 
one half pure cement and one half flint sand, floated over the entire 
surface as a finish. 

450h. Clinkers.—The clinkers produced by burning street 
sweepings and garbage and the debris produced in the manufacture 
of gas, consisting of the clinkers, old retorts, fire-bricks, ash-pan 
and coke refuse, have all been tried for paving both footpaths and 
carriageways; in the former they are generally satisfactory, but in 
the latter they quickly fail. 

The materials are prepared for use by crushing to a size of. 
about one inch; the crushed material is screened; the portion that 
will not pass through a one-quarter inch screen is used for the top 
finish, and the coarser portion for the foundation. The materials 
so separated are mixed with either Portland cement or coal-tar, and 
laid in place in the usual manner; or they may be formed into 
blocks at a factory and shipped to the place of use. 



CHAPTER IX. 


FOUNDATIONS. 

451. The stability, permanence, and maintenance of any pave¬ 
ment depends upon its foundation. If the foundation is weak, the 
surface will quickly settle unequally, forming depressions and ruts. 
With a good foundation the condition of the surface will depend 
upon the material employed for the pavement and the manner of 
laying it. 

452. The essentials necessary to the forming of a good founda¬ 
tion are: 

(1) The entire removal of all vegetable, perishable, and yielding 
matter. It is of no use to lay good material on a bad substratum. 

(2) The drainage of the subsoil wherever necessary. A perma¬ 
nent foundation can only be secured by keeping it dry; for, where 
water is allowed to pass into and through it, its weak spots will be 
quickly discovered and settlement will take place. 

(3) The thorough compacting of the natural soil by rolling with 
a roller of proper weight and shape until it forms a uniform and 
unyielding surface. 

(4) The placing on the natural soil so compacted a sufficient 
thickness of an impervious and incompressible material which will 
effectually cut off all communication between the soil and the bot¬ 
tom of the pavement. 

453. The character of the natural soil over which the roadway 
is to be built has an important bearing upon the manner of forming 
and the kind of foundation; each class of soil will require different 
treatment. Whatever its character, it must be brought to a dry and 
tolerably hard condition by draining and rolling. Sands and 
gravels which do not hold water present no difficulty in securing a 
solid and secure foundation; clays and soils retentive of water are 
the most difficult. Clay should be excavated to a depth of at least 

18 inches below the surface of the finished covering, and the space 

245 


246 


HIGHWAY CONSTRUCTIONS 


so excavated filled in with sand, furnace-slag, ashes, coal-dust, 
oyster-shells, broken brick, or other materials which are not exces¬ 
sively absorbent of water. Whichever of these materials is used, it 
should be thoroughly consolidated before laying the pavement. 

In ground saturated with water a foundation may be formed of 
logs or layers of fascines; but unless the nature of the ground is 
such as will always insure the timber being kept in a wet or damp 
state, it will soon rot and the road will go to pieces. Therefore they 
should never be employed unless under unavoidable circumstances. 

454. Sand.—Sand and planks, gravel, and broken stone have 
been successively used to form the foundation for pavements; but 
although eminently useful materials, their use for this purpose has 
been and always must prove a failure. They are inherently weak 
and possess no cohesion, and the mam reliance both for strength 
and wear must be placed upon the surface-covering. This cover¬ 
ing, being usually (except in case of sheet asphalt) composed of 
small units with joints between them varying from one half to one 
and a half inches possesses no elements of cohesion, and under the 
blows and vibrations of traffic the independent units or blocks will 
settle and be jarred loose. They are porous and the subsoil quickly 
becomes saturated with urine and surface-waters percolating 
through the joints; winter frosts upheave them and the surface of 
the street becomes blistered and broken up in dozens of places. 
The defects of plank foundations are stated in Art. 186. 

Although sand, gravel, etc., by themselves are unsuitable as 
foundation materials for block pavements, still when used with 
judgment they form excellent foundations for broken-stone roads. 

455. Sand Foundation.—The natural soil having been trimmed 
and thoroughly compacted by rolling to the cross-section which is 
to be given to the covering, a layer of sand four inches thick is 
spread uniformly, thoroughly wetted by sprinkling, and rolled; 
two other layers of four inches each are in like manner added and 
rolled. The compression effected by a roller weighing ten tons will 
reduce the thickness of twelve inches to eight a greater final thick¬ 
ness than this is unnecessary unless the natural soil is very yield¬ 
ing, when it may be increased to twelve or sixteen inches. 

456. Blast-furnace Slag.—The ordinary brittle slag makes a, 
very good foundation for a road, particularly on clay or wet soils, 
as by rolling the top pieces form a powder that fills the interstices 




FOUNDATIONS. 


247 


between the lower fragments so thoroughly that neither clay nor 
mud can work up through the layer, and on this the more durable 
wearing materials can be placed. It was found impossible to form 
any roads on the soft clay surface of the Centennial Fair grounds 
at Philadelphia until their beds had been prepared by a layer of 
well-rolled furnace-slag, after which they stood heavy teaming 
without under-drainage; the binding of the fragments of slag with 
the thorough filling of the interstices preventing any mud from 
working up through the first or cover layer, thus keeping the road 
from breaking up. 

457. Concrete.—As a foundation for all classes of pavement 
(broken stone excepted) hydraulic-cement concrete is superior to 
any other. When properly constituted and laid it becomes a solid 
coherent mass capable of bearing great weight without crushing, 
and which if it fail at all must fail altogether. It is the most 
costly, but this is balanced by its permanence and saving in the 
cost of repairs to the pavement which it supports. It admits of 
access to subterraneous pipes with less injury to the neighboring 
pavement than any other, for the concrete may be broken through 
at any point without unsettling the foundation for a considerable 
distance around it, as is the case with sand or other incoherent 
material; and when the concrete is replaced and set, the covering 
may be reset at its proper level without the uncertain allowance for 
settlement which is necessary in other cases. 

458. Thickness of Concrete—The thickness of the concrete bed 
must be proportioned by the engineer; it should be sufficient to 
provide against breaking under transverse strain caused by the set¬ 
tlement of the subsoil. On a well-drained soil six inches will be 
found sufficient, but in moist and clayey soils twelve inches will 
not be excessive. On such soils a layer of sand or gravel, spread and 
compacted before placing the concrete, will be found very bene¬ 
ficial. 

459. Concrete (called- beton by the French engineers) is a 
species*of artificial stone composed of (1) the matrix, which may 
be either lime or cement mortar, usually the latter, and (2) the 
aggregate, which may be any hard material, as gravel, shingle, 

broken stone, shells, brick, slag, etc. 

The essential quality of concrete seems to be that the material 
of the aggregate should be of small dimensions, so that the cement- 



248 


HIGHWAY CONSTRUCTION. 


ing medium may act in every direction round them, and that the 
latter should on no account be more in quantity than is necessary 
for that purpose. The aggregate should be of different sizes, so 
that the smaller shall fit into the voids between the larger. This 
requires less mortar and with good aggregate gives a stronger con¬ 
crete. Broken stone is the most common aggregate. 

It is usual to require that the stone shall be broken so as to 
pass any way through a 2-inch ring. To insure compact packing 
the aggregate should consist of a mixture of broken stone ranging 
from 1 to 3 inches, and pebbles which are at least equal to the 
strength of the mortar. Sun-dried or rain-soaked material is to be 
strictly avoided. The choice of the cementing substance, lime or 
cement, depends upon the use of the concrete. 

460. The strength of concrete depends upon the cohesion of 
the matrix, adhesion to the aggregates, irregular bonding or inter¬ 
locking of the coarser fragments, and upon the strength and 
proportion of each ingredient. 

Concrete for pavement foundations should be dense and homo¬ 
geneous, with the voids of the aggregate thoroughly filled with 
mortar, and the latter must again be so constituted that the voids 
between the grains of sand shall be closely filled by the cement 
paste. 

Good concrete has a specific gravity of 1.5 to 2.5, according to 
its composition of crushed bricks or heaviest stones, A cubic yard 
weighs from 2500 to 3900 pounds. 

461. Proportions.—The proportions of the ingredients required 
for the manufacture of concrete may be ascertained by measuring 
the respective voids. 

The proportion of voids may be determined by experiment in 
either of the ways described in Art. 373, page 207. 

The voids of broken stone, in which the size and shape of the 
pieces are nearly uniform, are about 0.5 of the mass. If the pieces 
are not uniform, the voids are about 0.4 of the mass. The voids in 
gravel vary, but average about 0.5 of the mass. 

462. The voids between the grains of sand will probably average 
33 per cent; that is to say, 67 per cent of the cubic contents to be 
occupied by the mortars are absorbed by the solids of the grains of 
sand and 33 per cent are to be filled in with cement, so that a 
mortar of one part of cement to two of sand, and no more, is 



FOUNDATIONS. 


249 


required for water-tight work. A strong water-tight concrete 
will contain by volumes as follows: cement, sand, stone, as 
1:2:5; and with fine Portland this mixture may reach after 
four weeks a compressive strength of 175 tons per square foot. 
The eight volumes of material fill finally a space of about 5.2 
volumes. 

463. The addition of water must be limited to the actual 
requirements, which fluctuate for natural cements between 50 and 
55 per cent, and for Portland cement between 40 and 45 per cent, 
of the weight of the cement used. Plasticity is only to be attained 
by diligently tamping an apparently dry mass until water appears 
on the surface. 

464. The following are some of the more usual proportions: 


American hydraulic cement. 1 part 

Sand...2 parts 

Broken stone. 3 


Portland cement, 

Sand. 

Broken stone.... 


,... 1 part 
.... 3 parts 
5 to 7 “ 


Portland cement. 1 P art 

Sand. 21 parts 

Gravel. . 3 

Broken stone .*.5 


Tests of this formula showed a filling of voids within 6$ of the 
whole volume. One barrel of cement weighing 380 pounds net made 
1.18 cubic yards of concrete weighing when dry 136 pounds per 

cubic foot. Cost per cubic yard, $6. 

For one cubic yard of concrete of stone, gravel and sand, with¬ 
out voids, the following quantities of materials are required: 


Broken stone 50$ of its bulk voids 
Gravel to fill voids in the stone... 
Sand “ “ “ gravel... 

Cement “ “ “ sand 


1.00 

.50 

.25 

.125 


cubic yard 

i i i ( 


<i <e 


For one cubic yard of concrete of stone and sand without voids, 
the following quantities of materials are required: 


Broken stone 50$ of its bulk voids 
Sand to fill voids in the stone. 


Cement “ 


sand. 


1.00 cubic yard 
.50 “ 

.25 “ 























250 


HIGHWAY CONSTRUCTION. 


465. Mixing. —The concrete may be mixed by hand or by ma¬ 
chinery. In the first method the cement and sand are mixed dry. 
About half the sand to be used in a batch of concrete is spread 
evenly over the mortar board, then the dry cement spread evenly 
over the sand, and then the remainder of the sand is spread on top 
of the cement. The sand and cement are then mixed with a hoe 
or by turning and re-turning with a shovel. It is very important 
that the sand and cement be thoroughly mixed. A basin is then 
formed by drawing the sand and cement to the outer edges of the 
box, and the water is poured into it. The sand and cement are 
then thrown back upon the water, the whole mass thoroughly 
mixed with the hoe or shovel, and then levelled off. The broken 
stone should be sprinkled with sufficient water to remove all dust 
and thoroughly wet the entire surface. The amount of water 
required will vary considerably with the absorptive power of the 
stone and the temperature of the air. The wet stone is then to be 
spread evenly over the top of the mortar, and the whole mass 
thoroughly mixed by turning up with a shovel. When the aggre¬ 
gate consists of broken bricks or other porous material it should be 
thoroughly wetted and time allowed for absorption previous to use; 
otherwise it will take away part of the water necessary to effect 
the setting of the cement. 

466. Laying.—After mixing, the concrete is conveyed in wheel¬ 
barrows and compacted in position by ramming in layers. When 
the thickness is to be 6 inches it should be laid in one layer; if 
thicker, in two equal layers, the surface of the first layer being 
moistened before spreading the second. If too much water has 
been used in mixing, it will be impossible to compact it by ram¬ 
ming; AVhen ready for use the concrete should be quite coherent 
and capable of standing at a steep slope" without the water running 
from it. Hamming, when properly done, consolidates the mass 
about 5 or 6 per cent, rendering it less porous, and very materially 
stronger. The rammers are, like those used in street-pav\ng, of 
wood, about 4 feet long, 6 to 8 inches in diameter at foot, with a 
lifting-handle, and shod with iron; weight about 35 pounds. They 
are let fall six or eight inches. The men using them, if standing 
on the concrete, should wear india-rubber boots to protect their 
feet from corrosion by the cement. 

The ramming should be continued only until the water begins 




FOUNDATIONS. 


251 


to ooze out on the upper surface. Too severe or long-continued 
pounding injures the strength of the concrete by forcing the broken 
stone to the bottom of the layer, and by disturbing the incipient set 
of the cement. When the concrete is rammed, walking should not 
be permitted on it for at least 12 hours; 24 would be better. It is 
necessary to give the concrete abundance of time to dry and set. 
This precaution is indispensable. If an undue amount of moisture 
should remain after the superstructure is laid, it will destroy the 
homogeneous qualities of the concrete. 

487. A correctly proportioned concrete has fully as much 
strength as the cement-mortar used in mixing it. By diminishing 
the aggregate below the calculated quantity the cost of concrete is 
increased without benefit to strength. 

The transverse strength of concrete ranges between 50 and 400 
pounds, depending upon the character of the cement and skilful¬ 
ness of manipulation. 

468. Compressive Strength.—Trautwine says that cubes of Port¬ 
land cement, sand, and broken stone, “ well made and rammed, 
should, either in air or in water, require to crush them at different 
ages not less than about as follows: 

Age iu months. 1 3 6 9 12 

Tons per square foot. 15 40 65 85 100 

Under favorable conditions of materials, workmanship, and weather, 
the strengths may be from 50 to 100 per cent greater." 

The compressive strength of 6-inch cubes of concrete exposed 
to the air for six months, as determined in connection with the 
construction of the St. Louis Bridge, was as follows: with the 
proportions of 1 part cement (Akron and Louisville), 1 part sand, 
and 4 parts broken limestone, the mean compressive resistance for 
nine trials was 1200 pounds per square inch (85 tons per square 
foot); and with the proportions of 1, 2, 4, respectively, the average 
resistance for twelve trials was 940 pounds per square inch (70 tons 
per square foot). 

Tests with the United States testing-machine at Watertown, 
Mass., between steel gave an average of 1544 pounds per square 
inch (110 tons per square foot) for 4-inch to 6-inch cubes of con¬ 
crete 46 months old composed of 1 part Rosendale cement-paste, 
lj parts sand, and 6 parts broken stone. Under the same condi- 





252 


HIGHWAY CONSTRUCTION. 


tions, concrete composed of 1 part Rosendale cement-paste, 3 parts 
sand, and 6 parts broken stone stood 1021 pounds per square inch 
(73 tons per square foot). Another sample of cement gave 1078 
pounds per square inch (77 tons per square foot) for concrete 22 
months old composed of 1 part cement paste, 3 parts sand, and 4 
parts broken stone. Ten experiments with a single sample of 
Portland cement gave 3067 pounds per square inch (219 per square 
loot) for concrete composed of 1 part cement paste, 3 parts sand, 
and 6 parts broken stone. The concrete under the Washington 
monument, composed of 1 part Portland, 2 parts sand, 3 parts peb¬ 
bles, and 4 parts broken stone, when six months old stood 2000 
pounds per square inch (144 tons per square foot). 

Experiments made in connection with the construction of the 
Vyrnwy dam—built to impound water for the supply of Liverpool, 
England—gave an average strength from six experiments, for cubes 
of mortar composed of 1 part Portland cement and 2 parts of sand 
from 32 to 37 months old, crushed between jfine cushions 4 inch 
thick, of 4428 pounds per square inch (284.7 tons per square foot); 
and cubes of concrete composed of gravel and sufficient mortar com¬ 
posed as above to fill the interstices gave an average strength, for 
two cubes 35 and 36 months old, of 3497 pounds per square inch 
(224.9 tons per square foot). The blocks were made from the con¬ 
crete actually used in the work, and were moulded by ordinary work¬ 
men without supervision, with the intention of securing blocks repre¬ 
sentative of the concrete as laid in the Avork. For cubes of the con¬ 
crete tested between “ mill-boards ” (straw-boards) the same series 
of experiments gave results as follows: 


Age of the Blocks. 

Number of 

Mean Crushing Strength. 



Months. 

Experiments. 

Lbs. per sq. iu. 

Tons per sq. ft. 

32-36 

3 

2.365 

170.4 

20-30 

6 

2,278 

164.0 

5-8 

2 

1,742 

125.5 

1-24 

7 

1,477 

106.4 


469. Cost.—The cost of concrete varies greatly, depending upon 
the kind of mortar, whether lime or cement; upon the richness 



















FOUNDATIONS. 


253 


of the mortar; upon the proportion of aggregate to mortar, upon 
the cost of the ingredients and of the labor, etc. 

It varies from $4.00 to $6.00 per cubic yard with Rosendale 
cement, and from $6.00 to $9.00 per cubic yard with the Portland 
cement. The cost for pavement foundations ranges from 94 cents 
to $1.50 ]3er square yard. 

Portland-Cement Concrete. 


Proportions: 

Cement. 1 part 

S au( i.- • • • . 3 parts 

Broken stone.. 5 “ 

Portland cement. 1.28 bbls. at $2.60 — $3.33 

Sand.. 0.50cu. yd. “ 1.30 = 0.65 

Broken stone... 0.90 “ ‘ 1.23 — 1.12 

Labor.,.0.91 day “ 1.75 = 1.59 

Foreman . 0.07 “ “ 3 00 = 0.21 


Total cost of one cubic yard in place.$6.90 


470. An excellent concrete is made of 80 parts of furnace-slag 
(crushed) and 20 parts of asphaltic cement; the slag and cement 
should be heated before mixing, and be laid while hot. 

471. As the value of concrete depends principally upon the ma¬ 
trix or cementing medium, a thorough knowledge of the mortar 
and the characteristics of its ingredients is indispensable for suc¬ 
cessful manipulation. 

The material employed for the manufacture of mortar are: 

(1) Lime (common and hydraulic). 

(2) Hydraulic cements (natural and artificial). 

(3) Sand. 

472. Common Lime is derived from the calcination of pure 
and impure limestones, and is extensively employed for the manu¬ 
facture of mortar used in building construction. It is unsuitable for 
the manufacture of concrete. Concretes in which it is used as a 
matrix are permeable, weak, and liable to rupture from sudden 
shock. Lime mortar sets or hardens slowly, and if deprived of air 
setting may never take place, as it hardens mainly through the aid 
of carbonic acid gas, which it absorbs slowly from the atmosphere. 

Hydraulic Lime is in many respects similar to common lime, 
but possesses the property of hardening under water. This class of 














254 


HIGHWAY CONSTRUCTION. 


lime is much used in Europe, but there is none produced in the 
United States. 

473. Hydraulic Cement is of two classes, natural and artificial. 
The American natural or Rosendale type of cement is made by 
burning in ordinary draw-kilns cement rock composed of limestone 
intimately mixed with silica, alumina, magnesia, etc., and grinding 
the calcined product to powder. The cement thus produced 
depends for its uniformity upon the homogeneity of the rock from 
which it is made. 

These cements are of a porous, globular texture, with a specific 
gravity of about 2.7. They do not heat up nor swell sensibly whilst 
they are mixed; they set quickly in air, but harden slowly, under 
water, without shrinking, and attain great strength with well-de¬ 
veloped adhesive force. 

Color .—The color of these cements gives no clue to their ce¬ 
mentitious value, since it is chiefly due to oxides of iron and man¬ 
ganese, which bear no direct relation to the hydraulic properties. 

To insure efficient chemical action in hardening, the grinding 
must be carried to the production of impalpable powder. These 
cements bear admixture of sand to double their own volume and 
over. For mixing pure cements from 30 to 40 per cent of water 
must be added. 

Many American cements of this class contain large percentages 
of carbonate of magnesia. Pure carbonate of magnesia, when 
burned at a moderate heat, ground to fine powder, and made into 
paste with sea-water, makes a cement which is superior in hardness 
and strength to any other, not excepting even Portland cement. 
These cements give good adhesion to stones and bricks, because 
they part with their surplus water more slowly than the others. 
Whenever judiciously selected and conscientiously manipulated 
they have given full satisfaction. Many causes co-operate in affect¬ 
ing rocks of the compound character required for the production of 
hydraulic cements. Deleterious material is disseminated through 
the various strata of a quarry in constantly and widely changing 
proportions, each stratum exhibits heterogeneous features. Hence 
it taxes judgment, begotten of large experience, honesty, careful¬ 
ness, and skill, to keep up reasonably uniform quality. 

Different quarries show dissimilar stones. The best brands vary 
greatly in chemical composition. Fineness, density, thorough and 



FOUNDATIONS. 


255 


homogeneous mixture, humidity, accessory ingredients, enter largely 
into the problems. 

To preserve the activity and strength of the natural cements, 
air and moisture must be excluded by careful packing and dry 
storage of the barrels; otherwise the premature development of 
carbonate of lime will interfere with the subsequent hydration. 

Prof. DeSmedt found for our native Virginia cements in pure 
state, after 30 days’ exposure, 170 to 250 pounds tensile strength 
per square inch, which increased in 11 months to 316 to 381 pounds. 
Mixed with equal proportions of sand he obtained from 116 to 155 
pounds and 180 to 190 pounds as above. 

Gillmore states the adhesion of Rosendale cement to front bricks, 
after 28 days, when pure to be 30 pounds, and when mixed with 
one or two parts of sand 16 and 12 pounds. 

Clarke reports the tensile strength of these Rosendale cements, 
pure, after one and twelve months, as 145 and 290 pounds respect¬ 
ively; when mixed 1 to 1, to 116 and 256 pounds; when mixed 1 to 
2, 60 and 180 pounds; and when mixed 1 to 3, 35 and 121 pounds 
after the same periods. 

One cubic foot of Rosendale cement weighs 49 to 59 pounds. 
The proportion of tensile to compressive strength averages probably 
after a month 1 to 4, and rises after two years about 1 to 6 or 7. 

The specifications of the Engineers’ Department of the District 
of Columbia require seven days after mixture, for neat, natural 
cement, 95 pounds, and for mixtures with one and two parts of sand 
56 and 22 pounds tensile strength per square inch, respectively. The 
gradual increase of strength by time is carefully noted and estab¬ 
lishes the reputation of the accepted brands. 

474. Natural Portland Cement.—Portland cement derives its 
name from the resemblance which hardened mortar made of it 
bears to a stone found in the isle of Portland, off the south coast of 
England. It is manufactured in those rare cases where rocks are 
traced which contain combinations of lime and silica of alumina in 
the chemical proportions and physical condition found necessary 

for producing artificial Portland. 

The treatment then differs from that of ordinary cement only 
in the higher temperature for burning. There are extensive works 
of this class around Perlmoos in Germany, Grenoble in France, etc. 

475. Artificial Portland Cement—Fully 95 per cent of all the 



256 


HIGHWAY CONSTRUCTION. 


Portland cement used at the present day is artificial. It is made 
by thoroughly mixing together, in suitable proportions, clay and 
finely pulverized carbonate of lime (either chalk, marl, or compact 
limestone), burning the mixture in kilns at a high temperature, and 
then grinding the burned product between ordinary millstones. The 
result is an impalpable, dense, drossy, steel-hard powder, having a 
specific gravity of 3.0 to 3.15. A few weeks'storage seasons the 
powder and makes it ready for use. 

As accessory ingredients, sulphate of lime and other combinations 
of sulphur occur in Portland cement, which, combining with seven 
chemical equivalents of water, and even more, cause considerable 
increase of volume. This explains why a large percentage of sul¬ 
phuric acid endangers the durability of hydraulic cements, while a 
small addition of it tends to increase their strength. 

If the contents of clay in Portland cement rise above 50 ]ier 
centum of the calcined lime (overclayed cement), complete vitrifica¬ 
tion is to be feared during the burning; the lack of cementing sub¬ 
stance (lime) is felt, and the cement becomes an inert mass unfit 
for use. On the other hand, an “ overtimed ” cement tends toward 
quick setting and blowing or expansion. These effects, due to the 
presence of free caustic lime, may be remedied by airing such 
cement for a day or more, when the caustic lime will absorb car¬ 
bonic acid from the air and become a neutral body for the cement. 
There is for each material one most favorable projiortion in which 
the tendencies to shrinking and to expanding neutralize each 
other, so that a good cement is the result. 

The chemical reactions require for cement burned at white heat 
only half as much water as those burned at moderate heat; this no 
doubt contributes to the superior strength of the Portland. Water 
in the proportion of 20 to 25 per cent of the weight of the cement 
generally suffices for mixing pure cement. Mixtures with sand, ac¬ 
cording to its dry or moist state, require increased quantities. By 
far the strongest mortar, with or without sand, results from mix¬ 
tures in a state of incoherent dampness, with no more plasticity 
than absolutely necessary for the work in hand. 

Too long-continued stirring or excess of water prevents setting, 
a paste being formed which slowly hardens by shrinkage, caused 
by evaporation and pressure, analogous to fat lime. 

Normal material and treatment result in slow and cool setting 



FOUNDATIONS. 


257 


but comparatively low adhesive power. The tensile strength in¬ 
creases for a slow-setting Portland cement gradually for about two- 
years, while the compressive strength increases for many years. 

All Portland cements bear the admixture of large quantities of 
sand, but an excess retards setting and reduces the tensile strength. 
Mixtures of 1, 2, 3, and 4 parts of sand to one part of cement 
showed one year after mixing a reduction of 25, 50, 00, and 70 per 
centum (Michaelis and GranPs tests). An excess of sand makes a 
harsh, raw mixture, difficult of manipulation and hence unsuitable 
for architectural work. 

Magnesia as a prominent ingredient of the limestone, used as 
raw material for producing Portland cement, acts badly, even 
treacherously. It does not harden hydraulically either with silica 
or with alumina; hence it remains as calcined magnesia, simply 
ballast, which lessens the quantity of hydraulic substances. Mixed 
with water it forms a hydrate of no high cementitious value. The 
absorption of water proceeds the slower the stronger the magnesia 
has been calcined. In consequence the hydration takes place at a 
time when the hydraulic hardening of Portland cement is virtually 
completed, and the swelling, due to larger masses of magnesia* 
causes a destruction of this cohesion already attained, and this has 
caused the collapse of bridges and buildings, and the crumbling of 
plastering on walls in France, according to the observations of 
Lechartier, Deville, and Calvert. This belated increase of volume 
escapes observation under the ordinary tests for expansion and re¬ 
quires special caution. Portland cements containing more than >> 
per cent of magnesia should be rejected. 

476. Characteristics of Portland Cement. 

Color .—The color should be a dull greenish gray, caused by the 
dark ferruginous lime and the intensely green maganese salts. Any 
variation from this color indicates the presence of some impurity . 
blue indicates an excess of lime; dark green, a large percentage of 
iron; brown, an excess of clay; a yellowish shade indicates an 

underburned material. 

Fineness .—It should have a clear, almost floury feel in the hand; 
a coarse, gritty feel denotes coarse grinding. The fineness should 
be such that 80 per cent will pass through a sieve of 2500 mesnes 
to the square inch. 

Weight .—It should weigh from 84 to 88 pounds per cubic foot. 



258 


HIGHWAY CONSTRUCTION" 


A cement weighing from 70 to 80 pounds per cubic foot is invari¬ 
ably a weak one, though it may be of the requisite fineness; at the 
same time a heavy cement if coarsely ground is also weak and will 
have no carrying capacity for sand. 

Light weight may be caused by laudable fine grinding, or by 
objectionable underburning. In testing, weight and fineness must 
be taken in conjunction. 

Specific Gravity, between 3 and 3.05. As a rule the strength of 
Portland cement increases with its specific gravity. 

Tensile Strength .—When moulded into a briquette and placed 
in water for seven days it should be capable of resisting a tensile 
strain of from 300 to 400 pounds per square inch. 

Setting .—A pat made with the minimum amount of water 
should set in not less than three hours nor take more than six 
hours. 

Expansion and Contraction .—Pats left in the air or placed in 
water should during or after setting show neither expansion nor 
contraction, either by the appearance of cracks or change of form. 

A cement that possesses the foregoing properties may be con¬ 
sidered a fair sample of Portland cement and would be suitable for 
any class of work. 

Portland cement, although the best material that can be used as 
a cementing medium, should not be used by any one who is not pre¬ 
pared to take the trouble and incur the trifling expense of testing 
it; because if manufactured with improper proportions of its con¬ 
stituents, or improperly burnt, it may do more mischief than the 
poorest lime. 

477. Cement Tests.—As the value of cements varies greatly with 
their physical properties, and since one lot of cement is liable to 
differ very much from another lot of the same brand, it is necessary, 
in order to obtain an idea of their relative merits, to make a series 
of tests as to the effect that the amount of sand, water, temperature, 
pressure, age, etc., has upon them. 

How to carry out and interpret the results of various tests of 
cements involves great care and study and erroneous conclusions 
may be arrived at when undertaken by those not thoroughly ac¬ 
quainted with the subject and with the particular cements to be 
tested. 




FOUNDATIONS. 


259 


478. The properties of a cement which are usually examined to 
determine its constructive value are (1) color, (2) weight, (3) activity, 
(4) soundness, (5) fineness, and (6) strength. The last three are the 
most important. 

479. Color.—As previously stated, the color of American natural 
cements has no influence upon its quality. The color of these 
cements is generally brown, ranging from very light to dark brown. 
Sometimes a very light color indicates an inferior or underburned 
rock. With Portland cement it is different; the color has an im¬ 
portant bearing upon its quality; it should be dull greenish gray, 
and any deviation from this indicates impurities, as stated in Art. 
476. 

480. Weight .—For any particular cement the weight varies 
with the degree of heat in burning, the degree of fineness in grind¬ 
ing, and the density of packing. Other things being the same, the 
harder-burned varieties are the heavier. The finer a cement is 
ground the more bulky it becomes, and consequently the les3 it 
weighs. 

The weight per unit of volume is usually determined by sifting 
the cement into a measure as lightly as possible, and striking the 
top level with a straight-edge. In careful work the height of fall 
is specified. Since the cement absorbs moisture, the sample must 
be taken from the interior of the package. The weight per cubic 
foot is neither exactly constant, nor can it be determined precisely; 
and for the practical purpose of the user is of very little service 
in determining the value of a cement. However, it is often speci¬ 
fied as one of the requirements to be fulfilled. 

481. The following values, determined by sifting the cement 
with a fall of three feet into a box having a capacity of one tenth 
of a cubic foot, may be taken as fair average for ordinary cements. 
The difference in weight for any particular kind is mainly due to a 
difference in fineness. 


Portland, English and German.77 to 90 lbs. per cu. ft. 


“ fine ground French. 

“ American. 

Rnman .. 

.. 54 

4 < 

44 

4 4 

44 

44 

4 C 

4 C 

44 

44 

T^ncpn rl *A 1 p ••••••< 

..49 to 56 

4 4 

4 4 

44 

Lime of Teil . 


44 

44 

u 












260 


HIGHWAY COHSTRUCTIOH. 


Since a bushel is 1.244 cubic feet, the weight per bushel can 
be approximately obtained by adding 25 per cent to the above 
quantities. However, it is better to make the cubic foot the standard 
unit measure. 

482. Activity .—A mortar is said to have set when it has at¬ 
tained such a degree of induration that its form cannot be altered 
without causing a fracture, i.e., when it has entirely lost its plas¬ 
ticity. Some cements set quickly, while others are comparatively 
slow in developing the first indications of hydraulicity. This 
property is called hydraulic quickness or activity. A quick-setting 
cement is especially valuable in constructions under water. 

A distinction should be carefully made between hydraulic ac¬ 
tivity and hydraulic energy or strength. The former refers to the 
time required to attain a small degree of strength, and the latter to 
the amount of strength ultimately attained. There is no necessary 
relation between time of setting and ultimate strength; but, as a 
general rule, the slow-setting cements ultimately attain to a greater 
strength than quick-setting ones. 

The activity of cement may be increased by adding a quicker- 
setting cement, as plaster of paris, lime, clay, or even grease,—all 
such ingredients, particularly the last, weakening the resulting 
mortar. 

483. “ The effects of a variation of temperature upon the hy¬ 
draulic quickness of mortars—whether derived from hydraulic 
cement, a mixture of common lime and pozzuolana, or produced 
by artificial means—is very marked: so much so, indeed, that in all 
comparative tests of this kind it is important to adopt some fixed 
standard of temperature, not only for the water with which the 
cement is mixed, as well as that in which the cement is immersed, 
but for the dry ingredients and the surrounding atmosphere. All 
cements are not equally sensitive to a variation of temperature.” 

The rise in temperature is much more apparent in the setting 
of quick-setting cements than in others, because the external cool¬ 
ing is relatively much less. 

Herzog obtained the following results concerning the rise in 
temperature of a Portland cement, which he formed while wet into 
a prism 10 centimeters long and at another time into a prism 20 
centimeters long. In each case the original temperature was 13.5 
degrees C. 



FOUNDATIONS. 


261 


Ten Centimeters Long. 


Immediately after moulding.16 degrees C. 

After 30 minutes. 17 “ “ 

“ 70 “ .17 5 <« 

“ 4 hours . 18 ** «« 

5 “ ..18.5 “ 

6 “ .23.5 “ •* 

** 7 hours and 30 minutes.. .27 “ et 

** 8 “ max .29.5 “ “ 


Twenty Centimeters Long. 


Immediately after moulding.19 degrees C. 

After 1 hour and 30 minutes.20.5 “ “ 

“ 2 “ “ 30 “ .22 “ “ 

*« 4 *« “ 30 “ ..24 “ “ 

<f 5 “ “ 30 “ . 38 

e< 7 ** . .43 

8 s< . . 45 “ « 

“ 8 “ and 30 minutes, max .45.5 “ “ 


Thus we see that the temperature increased 16 degrees in one 
case and 32 degrees in the other; accordingly the rise in tempera¬ 
ture was proportional to the side of the cement-prism. Thus it 
will he seen that all theories about the rise in temperature of set¬ 
ting cements have no value unless they take the volume of cement 
into account. 

484. The quantity of water used in gauging the cement has 
great influence upon the tensile strength and must be regulated 
according to the kind of cement, since every cement has a certain 
given capacity for water; of course, however, in practice a quantity 
that is somewhat greater than this must generally be used. 

In the following table by Feichtinger it will be seen that 
the amount of water absorbed from the air by Portland cements 
(column 1) and hydraulic limes (columns 2, 3, 4) varies consider¬ 
ably with the time. 

In practice about 50 per cent of water is generally used, which is 
a great excess, so that there is usually about 30 per cent of water to 
be driven off by evaporation. If an undue amount be emjfloyed, the 
tensile strength is reduced to a considerable extent. On the other 
hand, if the quantity be as small as possible consistent with proper 
manipulation, the result will be much higher. From numerous 























262 


HIGHWAY CONSTRUCTION. 


TABLE XLIV. 

Amount of Water Absorbed by Cement and Lime. 



1 per cent. 

2 per cent. 

3 per cent. 

4 per cent. 

Fresh ground. 

.99 

1.28 

.61 

6.79 

After 4 hours. 

1.41 

1.67 

.71 

7.80 

“ 20 “ . 

2.29 

2.08 

1.14 

8.26 

‘ ‘ 3 days. 

5.62 

3.42 

1.82 

8.07 

* i rj it 

6.58 

3.85 

2.15 

11.20 

“ 14 “ . 

7.96 

4 46 

2.63 

11.80 

“ 28 “ . 

10.52 

8.30 

6.20 

14.48 

“80 “ . 

11.56 

9.50 

7.40 

14.65 


experiments it has been found that, as a general rule, a proportion 
of 1 part of water to 3 parts of cement by measure, or 1 to 3^ by 
weight, is the best, both as regards convenience of mixing and 
results. With a much less quantity the gauging would be so stiff 
as to render the manipulation most difficult; the risk of air-holes,, 
the reduction of which to a minimum is a point to be particularly 
attended to, would be augmented; the angles of the mould would 
be imperfectly filled, and generally a very imperfect briquette 
formed. Consequently the results of such tests would be unsatis¬ 
factory and unreliable. In general practice it will be found that a 
slight variation in the above-mentioned proportions will be neces¬ 
sary, depending upon the age and degree of fineness of the cement, 
but only to a limited extent. 

485. Effect of Age on the Cement.—The age of Portland 

cement, although strictly not a condition of manufacture, is an 
important element in its economical and safe use. Cement not 
only improves generally by keeping, but the older the cement the 
less danger will there be of its blowing, as the free lime would be 
acted upon by the atmosphere, causing it to slake and reducing the 
danger and expansion to a minimum. The age has also been 
found to exert considerable influence upon the rate of setting, 
causing it to require a much longer time to set than new cement. 

486. Tests of Activity.—To test hydraulic activity, mix cement 
with 25 to 30 per cent of its weight of clean water having a tem¬ 
perature of between 65 and 70 degrees Fahr., to a stiff plastic 
mortar, and make one or two cakes or pats two or three inches in 
diameter and about | inch thick. As soon as the cakes are pre- 

























FOUNDATIONS. 


2G3 


pared immerse in water at 65 degrees Falir., and note the time 
required for them to set hard enough to bear respectively a T V- 
inch wire loaded to weigh ^ of a pound and a g^-inch wire loaded 
to weigh 1 pound. When the cement bears the light weight, 
it is said to have begun to set; when it bears the* heavy weight, 
it is said to have entirely set. Cements, however, will increase 
in hardness long after they can just bear the heavy wire. The 
activity of the cement is measured by the interval which elapses 
between the time when the first weight is supported and that when 
the second is just borne. Notice that with the wires as above the 
weight per unit of surface in the second case is 16 times as much 
as in the first. Hence it is not necessary to have the diameters as 
stated, but only to have the pressure per unit of area 16 times greater 
in the one case than in the other. The same wire may be used in 
both tests, the load only being varied. Different kinds and 
brands of cement vary greatly in the time required to set. Some 
brands of Rosendale cement will support the heavy wire in two 
minutes, and some brands of Portland in not less than 12 hours. 
Cold retards the setting. Freshly-ground cements set quicker than 
old ones. The quick-setting cements usually set so that experi¬ 
mental samples can be handled within five to thirty minutes after 
mixing. The slow-setting cements require from 1 to 8 hours. 

487. Quick- and Slow-setting Cements.—Cements which set in 
less than half an hour are termed quick-setting, and those which 
do not set before two hours, slow-setting. These distinct defini¬ 
tions ought to be specially introduced in important specifications, 
where they will prevent misunderstandings as to what is meant by 
a slow-setting cement. Excepting special cases, slow-setting 
cements are more trustworthy. 

488. Soundness.—Soundness refers to the property of not 
expanding or contracting or cracking or checking in setting. 
These effects may be due to free lime, free magnesia, or to unknown 
causes. Testing soundnesses therefore determining whether the 
cement contains any active impurity. An inert adulteration or 
impurity affects only its economic value, but an active impurity 
affects also its strength and durability. 

The most simple test for detecting expansion in a cement is to 
make small pats with a trowel, about 3 or 4 inches square, and 
place them in water when sufficiently set, where they should 



264 


HIGHWAY CONSTRUCTION. 


remain a few days. If the cement be good, they will show no 
alteration in form; but any cracks showing on the edges, or other 
deviations from the original shape of the pats, indicate that the 
cement is of an expansive nature and therefore not to be trusted. 
But because a cement will not stand this test it is not in all cases 
to be condemned as useless, as its expansive or blowing property 
may be attributable to its being used too soon after leaving the 
mill. A proper process of cooling, placing it in a thin layer on a 
dry floor for a short time, will correct the defect. 

Contraction due to the cement being over-clayed may be 
detected by a similar test to that for expansion. 

The soundness of a cement may also be tested by placing some 
mortar in a glass tube (a swelled lamp-chimney is excellent for 
this purpose) and pouring water on top. If the tube breaks, the 
cement is unfit for use in damp places. A less delicate and less 
valuable test than either of the above is to note whether the 
cement heats when mixed with water. A thermometer is some¬ 
times used in making this test. 

The tests of soundness should not only be carefully conducted, 
but should extend over considerable time. Occasionally cement is 
found which seems to meet the usual tests for soundness, strength, 
etc., and yet after a considerable time loses all coherence and falls 
to pieces. 

489. Fineness.—The question of fineness is wholly a matter of 
economy. Cement, until ground, is a mass of partially vitrified 
clinker which is not affected by water and which has no setting 
power. It is only after it is ground that the addition of water 
induces crystallization. Consequently the coarse particles in a 
cement have no setting power whatever, and may for practical 
purposes be considered only as so much sand and essentially an 
adulterant. 

There is another reason why it should be well ground. A mor¬ 
tar or concrete being composed of a certain quantity of inert mate¬ 
rial bound together by a cementing material, it is evident that to 
•secure a strong mortar or concrete it is essential that each piece of 
aggregate shall be entirely surrounded by the cementing material, 
so that no two pieces are in actual contract. 

Obviously, then, the finer a cement the greater surface will a 
given weight cover, and the more economy will there be in its use. 







FOUNDATIONS. 


265 


Fine cement can be produced by the manufacturers in three 
ways: (1) by supplying the millstones with comparatively soft, 
underburnt rock which is easily reduced to power; (2) by running 
the stones more slowly, so that the rock remains longer between 
them; or (3) by bolting through a sieve and returning the un¬ 
ground particles to the stones. The first process produces an 
inferior quality of cement, while the second and third add to the 
cost of manufacture. 

490. Measuring Fineness.—The degree of fineness of a cement 
is determined by measuring the per cent which will not pass 
through sieves of a certain number of meshes per square inch. 
The committee of the American Society of Civil Engineers recom¬ 
mended the determination “by weight of the per cent that is 
rejected by sieves of 2500, 5476, and 10,000 meshes to the square 
inch respectively, the first-mentioned sieve being of No. 35, the 
second of No. 37, and the third of No. 40, wire gauge. These 
sieves are usually referred to by the number of meshes per linear 
inch; the first being known as No. 50, the last as No. 100. It is 
stated that, as sold, the number of meshes varies somewhat, and 
the number of wires is generally less by about 10 ten per cent 
than the number of the sieve. The diameter of the holes is about 
equal to the diameter of the wire. 

German Portland cements are commonly ground finer than 
English. “Most English manufacturers grind their cement to 
such a degree of fineness that when sifted through a sieve having 
2500 holes (50 by 50) to the square inch, it shall leave a residue of 
not more than 10 per cent by weight. Cement ground to this 
fineness will leave from 19 to 20 per cent of residue on a 4900 
(70 by 70) sieve, and practically nothing on a 625 (25 by 25) sieve.” 
This is supposed to be the most economical degree of fineness. 

Different brands of Rosendale cement vary considerably in their 
fineness. Those of the best reputation will leave from 4 to 10 per 
cent residuum on the No. 50 sieve; other brands, from 10 to 23 per 
cent. 

491. Strength.—Although in ordinary practice cements are 
subject only to compression, yet at the present time all tests are 
made with a view to ascertaining their tensile strength. The rea¬ 
son for this is that comparatively light strains produce rupture; 
and that when rupture does take place, the strain causing it is really 




266 


HIGHWAY CONSTRUCTION”. 


due to tension produced by the sinking of one part of the structure 
and not to compressive force. 

492. The Testing-machine.—The details of the form of the 
specimen to be tested (the briquette), as recommended by the Com¬ 
mittee of the American Society of Civil Engineers, are given in Fig. 
33. The method of placing the briquette in the machine is shown 
in Fig. 34. In applying the stress, it is also recommended to make 
the initial strain 0, and increase it regularly at the rate of 400 
pounds per minute until rupture takes place. “ For a weak mix¬ 
ture one half the speed is recommended.” 

There are many machines on the market, made specially for 
testing the strength of cement. Fig. 35 represents a cement-test¬ 
ing machine which can be made by an ordinary mechanic at an 
expense of only a few dollars. Although it does not have the con¬ 
veniences and is not as accurate as the more elaborate machines, it 
is valuable where the quantity of work will not warrant a more 
expensive one, and in many cases is amply sufficient. 

It was devised by F. W. Bruce for use at Fort Marion, St. 
Agustine, Florida, and reported to the Engineering News by Lieu¬ 
tenant W. M. Black, U. S. A. 

The machine consists essentially of a counterpoised wooden 
• lever 10 feet long, working on a horizontal pin between two broad 
uprights 20 inches from one end. Along the top of the long arm 
runs a grooved wheel carrying a weight. The distances from the 
fulcrum in feet and inches are marked on the surface of the lever. 
The clamp for holding the briquette for tensile tests is suspended 
from the short arm, 18 inches from the fulcrum. Pressure for 
shearing and compressive stresses is communicated through a loose 
upright, set under the long arm at any desired distance (generally 
6 or 12 inches) from the fulcrum. The lower clip for tensile 
strains is fastened to the bed-plate. On this plate the cube to be 
crushed rests between blocks of wood, and to it is fastened an up¬ 
right with a square mortise at the proper height for blocks to be 
J sheared. The rail on which the wheel runs is a piece of light 
T iron fastened on top of the lever. The pin is iron, and the pin¬ 
holes are reinforced by iron washers. The clamps are wood, and 
are fastened by clevis joints to the lever-arm and bed-plate respec¬ 
tively. When great stresses are desired, extra weights are hung on 





FOUNDATIONS. 


267 



Fig.33.FORM OF BRIQUETTE. 




Fig.34. 


CO 

SECTION AB 



A 


Fig. 35. 





























268 


HIGHWAY CONSTRUCTION. 


the end of the long arm. Pressures of 3000 pounds have been 
developed with this machine. 

493. Most of the tests made in this country and England are 
carried out for the purpose of ascertaining the strength of neat 
cements, although such material is rarely, if ever, used without the 
admixture of sand. In Europe, on the other hand, the practice was 
established about ten years ago, both by manufacturers and engi¬ 
neers, to determine the value of a cement by testing it when mixed 
with sand into mortar, the usual proportions of the mixture being 
three volumes of sand to one volume of cement. It is obvious that 
the latter practice is preferable, since thereby a knowledge of the 
strength and properties of the binding material actually used in 
the work will be gained, and furthermore because no valid infer¬ 
ence as to the cohesion of a mortar can be drawn from a statement 
of the tensile strength of the neat cement. 

Tests of this kind should, therefore, be made with cement 
mortar mixed in the same proportions as contemplated in the work 
itself, and also with the same sand if practicable, inasmuch as the 
quality of the latter exerts a marked influence upon the resulting 
strength of the mortar. In general, it may be said that the greater 
the proportion of sand in the mortar tested the more accurately 
can the actual cementing quality of the cement be indicated. 

494. Cement-mortar is composed of hydraulic cement and sand 
in varying proportions, depending upon the kind and quality of the 
cement. Cement-mortar differs from lime-mortar in its setting, in 
that it sets within itself without the aid of external elements. More¬ 
over, cement forms by the addition of water a chemical combination 
throughout all its parts, and setting or hardening takes place 
throughout the whole mass almost simultaneously. The strength 
of cement over lime mortar is shown by tests at the Watervliet 
(N. Y.) Arsenal to be about two to one in favor of the former. 

495. Quality of Mortar.—Good mortar should have plasticity 
when mixed with large quantities of sand, and after solidification 
compressive strength and tensile strength, as evidence of inde¬ 
pendent cohesion, power to resist the action of frost and heat, and 
adhesive qualities for cementing blocks into monolithic bodies. It 
is to be invariable in volume during and after solidification, to be 
weather-proof and, for hydraulic works, also water-tight. 

496. Quality of Sand.—The sand imparts crushing strength, 




FOUNDATIONS. 


269 


lessens shrinkage, and saves expense in lime-mortars. Hydraulic 
cements require sand only at exposed surfaces. Otherwise it serves 
as an adulterant for reducing a surplus of strength and density 
to actual requirements of a given bulk. The sand should be 
clean, sharp, large-grained, not too uniform in size, free from loan], 
vegetable or clayey substances, well screened, and, if necessary, 
washed. Admixed particles of clay adhere to the sand and form 
diaphrams between sand and mortar, which for durable harden¬ 
ing require close contact. 

Since sand is mostly used in greater quantities than the cement¬ 
ing substances, it equals them in importance. It is in all classes 
embedded in the matrix as a mechanical mixture. The tensile and 
crushing strengths of the same cement, with equal quantities of 
different qualities of sand, vary more than those of different brands 
of cement within the same group do among themselves. 

497. Quality of Water.—Fresh or salt water may be used in 
mixing the mortar, provided it is clean; but salt water may, with 
some natural cements, hinder the setting. 

498. Quantity of Water.—In regard to the proper amount of 
water to be used in tempering a cement-mortar, it may be said 
that this will depend upon the quality and quantity of sand, as also 
upon the quality of the cement. From the numerous and careful 
experiments with Portland and Rosendale cements, made a few 
years ago by Mr. Eliot C. Clarke, C.E., and published in the Trans¬ 
actions of the American Society of Civil Engineers for April, 1885, 
the inference was drawn that, “ as a rule, American cements re¬ 
quire more water than Portland, fine-ground more than coarse, and 
quick-setting more than slow-setting cements.” For experimental 
purposes in the laboratory, the amount of water added by Mr. 
Clarke to the dry mixture of sand and cement was usually about 
one fourth of the weight of the Portland and one third of the 
weight of the American cement contained in the batch; but these 
amounts were increased or diminished somewhat in order to obtain 
mortars of uniform consistency. Mr. Clarke adds, in mixing mor¬ 
tars on the site of public works, and particularly for concrete 
works, much larger quantities of water than are used by him for 
testing purposes are commonly added by workmen in order to 
render the labor of mixing and spreading less difficult, but that the 
result of this procedure is always a greater or less loss of strength. 





270 


HIGHWAY CONSTRUCTION". 


For the standard tests of cement-mortars by European engineers 
the rules prescribe one part by weight of cement, three parts by 
weight of normal sand, and four tenths of a part by weight of 
clean fresh water. 

499. Strength of Mortar. —Three classes of strength are re¬ 
quired in all mortars, viz., adhesive, compressive, and shearing. 
These strengths are all dependent upon the strength of the cement, 
the strength of the sand, and upon the adhesion of the former to 
the latter. 

500. Adhesive Strength. —It is commonly assumed that after 
the lapse of a moderate time the adhesive and cohesive strengths 
of cement-mortars are about equal, and that in old work the former 
exceeds the latter. Modern experiments, however, fail to establish 
the truth of this assumption, and indicate rather that the adhesion 
of such mortars to bricks or stones is much less than the tensile 
strength during the first few months; also that the relation be¬ 
tween the adhesive and cohesive strengths of both neat cements 
and mixtures with sand are very obscure. It has been found that 
the adhesion of mortars to bricks or stone varies greatly among the 
different kinds of these materials, and particularly with their po¬ 
rosity; it also varies with the quality of the cement, the character, 
grain, and quantity of sand, the amount of water used in tempering, 
the amount of moisture in the stone or brick, and the age of mor¬ 
tar. Some cements which exhibit high tensile strength give low 
values for adhesion, and conversely cements which are apparently 
poor when tested for cohesion show excellent adhesive qualities. 
Quick-setting cements are usually found to give greater adhesive 
strength than slow-setting ones, while in the case of cohesion the 
opposite is generally true. Under these circumstances, therefore, 
it is manifest that a test, at various stages of age, of the adhesive 
properties of a binding material like cement-mortar should be re¬ 
garded as a very important one, in the case of masonry structures 
which must soon after completion be subjected to other than com¬ 
pressive strains, and it is to be regretted that so comparatively 
little information respecting such tests with cements and mortars 
as made at the present time is available. 

To assist somewhat in arriving at a fair measure of the strength 
of hydraulic mortars at different periods of time, as well as the 
proper composition of the same, the statistics given in Table XLY 
have been compiled from a great variety of sources: 




FOUNDATIONS, 


271 


TABLE XLY. 


- 

0, 

JD 


V 

4-h 

V 

X 


1 

2 

3 

4 

5 

6 

7 

8 
9 

10 

11 

12 

13 

14 

15 
10 

17 

18 

19 

20 
21 
22 
231 
24 
251 
26; 
271 

28 i 

29 : 
30 


oo 

34 

35 

36 

37 

38 

39 

40 

41 

42 

43 

44 

45 

46 

47 
48: 
491 

50 

51 

52 

53 

54 

55 


Adhesive Strength of Mortars. 


Age in Days when 
Tested. 

Kind of Cement Used. 

Materials 
cemented to¬ 
gether. 

Neat 

Cement > 

vera 

strei 

pe 

tH 

4-T^ 

S ■o 
S 5 

<e A< 
gth 
r sq. 

t—i 

§ ■d' 

a s 

ihes 
m lb 
in. 

!-•. 

! a _r 

i ® ~ 

f § 

ive 

s. 

*a d 
a • 

i T3 

a s 

O 

Authority. 

7 

r* 

i 

Quick-setting cement 
Slow- “ “ 

Hard brick 

4 4 44 



*23 

*15 

.... 

.... 

Robertson, 1858 

bb 4b 

7 

7 

Portland 

44 

Sawed limestone 
Cut granite 

57 

41 

.... 


.... 


I. J. Mann, 1883 

bb bb .b 

7 

44 

Polished marble 

38 





*b bb bb 

7 

b 4 

Bridgewater brick 

19 





bb 4b 4b 

7 

Hydraulic lime 

Brick + 

24.1 

21 

18.7 

15.3 

13.2 

Dr. Bohme, 1883 

7 

Portland 

“ X 

168 

102 

38 

20 

9 

Prof. Warren, ’87 

7 


“ § 


117 

53 

26 

16 

bb bb bb 

16 

Quicklime 

Limestone 



9-15 



Roistard 

16 

Lime and cement 

4 4 



5 



bb 

28 

Hydraulic lime 

Brick t 

35. i 

30.4 

25.5 

20.9 

17.5 

Dr. Bohme, 1883 

28 

Portland 

“ X 

213 

105 

45 

24 

14 

Prof. Warren, ’87 

28 

4 4 

“ § 


146 

73 

48 

45 

bb 4b 4b 

30 

Quick-setting cement 

Hard brick 



*59 




30 

Slow- “ “ 

4b 44 



*30 



bb tb 

30 

Rosendale 

Croton brick 

30.8 

15.7 

12.3 

6.8 

5.2 

Gen. Gillmore, ’63 

30 

4 4 

Fine cut granite 

27.5 

20.8 

12.0 

9.2 

7.9 

bb 44 bb 

30 

Portland 

Sawed limestone 

78 





I J Mann 188<? 

30 

44 

Cut granite 

II 97 





bb bb b b 

30 

44 

Polished marble 

l| 71 





4b 4b 4b 

30 

44 

Bridgewater brick 

II 66 





bb 4b 4b 

30 

44 

Sandstone 

49 





bb 4b 4b 

30 

Blue lias lime 

Staffordshire brick 



*40 



Rnilrlinp* Wws ’80 

30 

44 44 44 

Gray stock brick 



*36 



• 4 4b bb 

30 

4 4 44 (4 

Common soft brick 



*18 



bb bb 4b 

30 

Lime and pozzuolana 

Hai’d brick 



*5 



J White 1832 

42 

Portland 

Brick 1 

68.8 

.... 

46.9 

. . . 

.... 

Bauschinger, 1873 

48 


“ If 


.... 

... 

24.2 


bb bb 

56 

44 

“ 1 


54 

56.9 



bb 4b 

90 

Hydraulic lime 

‘4 t 

39.3 

41.9 

38.9 

28.1 

22.6 

Dr. Bohme, 1883 

95 

Portland 

“ Hi 

.... 

. . . 

.... 

14 2 

... 

Bauschinger, 1873 

110 

Hydraulic lime 

“ 1; 

.... 

... 

.... 

12.8 

... 

b b 4 b 

180 

Quicklime 

44 



*33 



Rondolef. 1831 

180 

44 

Limestone 



*15 



b b bb 

180 

4 4 

Hai’d brick 



*40 



Robertson 1858 

180 

44 

Soft 



*18 



b b bb 

180 

Portland 

Sawed slate 

II 62 





T ,T Mann 188.3 

180 

44 

Portland stone 

II55 





b b bb bb 


(4 

Polished marble 

1175 





bb 44 bb 

270 

Lime and pozzuolana 

Hard brick 


*8 



J. White 1832 

320 

Rosen dale 

Croton brick 

68 

40 

24 



Gen. Gillmore, ’63 

lyr. 

Quicklime 

Not stated 




*21 

.... 

Vicat, 1818 

b 4 

Good quicklime 

4 4 4 4 




*51 


bb bb 

41 

Ordinary hydraulic lime 

4 4 4 4 



*85 

... 

.... 

bb b b 

44 

Good “ “ 




*140 



bb bb 

4 • 

44 44 44 

Materials in air 


70 




Mallet 1829 

4 4 

44 44 44 

“ “ water 


99 




bb bb 

44 

Portland 

Gault clay brick 









pressed 

45 

44 

... 

.... 

.... 

J. Grant, 1871 

44 

44 

Stock brick in air 

78 

63 




bb bb bb 

44 

44 

“ “in water 

96 

70 




bb bb bb 

44 

44 

Staffordshire blue 









brick in air 

48 

47 

, . , 

.... 


bb bb bb 

44 

44 

Staffordshire blue 









brick in water 

40 

29 

.... 

. . . . 


bb fcb bb 

44 

44 

Fareham red brick 









in air 

126 

83 




bb bb 44 

44 

44 

Fareham red brick 









in water 

123 

62 




bb (b 4b 


* Proportions of sand not given, but presumably about those indicated in headings of table. 
+ Standard sand used in mixture. % Clean river sand used in mixture. 

§ Crushed sandstone used in mixture. 1 Fine river sand used in mixture, 

il Coarse particles in cement sifted out before testing. 






























































































272 


HIGHWAY CONSTRUCTION. 


501. Shearing Strength.—In recent times elaborate experiments 
to ascertain the shearing strength of mortar, both in the joints of 
brickwork and separate blocks, have been made by Prof. Bausch- 
inger of Munich. The results are too numerous for a verbal 
description, and they are accordingly given in Table XLVI. None 
of the values obtained are very large, ranging after ninety days 
from 70 to 7 pounds per square inch on brickwork with mortar 
mixed in the proportion of three parts of relatively fine river sand 
to one of cement-lime. The shearing strength of cubes of mortar 
also appears to be considerably greater than that of the compara¬ 
tively thin joints in brickwork, and to be influenced by the quality 
of the sand. 


TABLE XLVI. 

Shearing Strength of Cements and Mortars. 


fl 

£ 

c/j 73 


Average Shearing Strength 
in lbs. per sq. in. 


c« 

Q v 
flH 

V 

bC 

< 

Kind of Cement. 

Neat 

Cement. 

Cement, 1. 
Sand, 1. 

Cement, 1. 
Sand, 2. 

Cement, 1. 
Sand, 3. 

Cement, 1. 
Sand, 4. 

Cement, 1. 
Sand, 5. 

Authority. 

42 

I. 

Shear in, and parallel 
to, bed-joints of brick- 
ivork. 

Portland (Bonn)*. 



72.5 




Prof. Bauschinger, 1873 

49 

4 4 44 :|c 

73.9 

... 

.... 

64 

.... 


52 

4 4 4 4 * 

.... 

155 

106.6 


• • • • 


44 44 44 

90 

“ (Perlmoos)*. 

• • • . 

, V , . 

• . . . 

22.7 



44 «4 44 

90 

Hydraulic lime*. 

.... 

. . . . 

. • • • 

76.8 

.... 


44 44 44 

90 

50 

Quicklime*. 

II. 

Shear in cubes of ce¬ 
ments and mortars 
dried in air. 

Portland (Bonn)*. 

369.7 

369.7 

284.4 

7.1 

142.2 



44 (4 44 

Prof. Bauschinger, 1873 

60 

“ (Perlmoos)t. 

256.0 

405.3 

383.9 

362.6 

320.0 



1 w’k 

% “ “ §. 

224.7 

.... 


108.1 


66.8 

“ “ 1878 

41 

II “ “ §. 

301.5 



123.7 


78.2 

44 44 44 

Svv’ks 

X “ “ §• 

270.2 

.... 


128 0 


93.9 

44 44 44 


II “ “ §. 

322.8 

.... 


163.5 


122.3 

44 44 44 

4w’ks 

X “ “ §. 

257.4 

.... 


153.6 


112.3 

44 44 44 

44 

II “ “ §. 

341.3 

. . 


199.1 


137.9 

44 44 44 

8w’ks 

X “ “ §• 

258.8 

... 


196.2 


167.8 

4 4 44 4 ; 

44 

11 “ “ §. 

376.8 



237.5 

.... 

199.1 

44 44 4w 


* Fine river sand. t Coarse sand. 


X Average values for series of four different brands of quick-setting cements. 
§ Clean, medium sand. 

!l Average values for series of four different brands of slow-setting cements. 






































































FOUNDATIONS. 


273 


As in the case of adhesion, no exact relation between the tensile 
and the shearing strengths of mortar placed in brickwork can yet 
be deduced, owing to thedack of sufficient data; but, on the other 
hand, the experiments show that the shearing strength of blocks or 
cubes of mortar is about 20 per cent greater than the tensile strength 
under the same circumstances. ♦ 

502. Compressive Strength.-—But few experiments have been 
made upon the compressive strength of mortar. An examination 
of the results of about sixty experiments made with the Watertown 
testing-machine seems to show that the compressive strength of 
mortar, as determined by testing-cubes, is from 8 to 10 times the 
tensile strength of the same mortar at the same age. Data deter¬ 
mined by submitting cubes of mortar to a compressive strain are of 
little or no value as showing the strength of mortar when employed 
in thin layers, as in the joints of masonry. The strength per unit 
of bed area increases rapidly as the thickness of the test-specimen 
decreases, but no experiments have ever been made to determine 
the law of this increase for mortar. 

503. Tensile Strength.—The following table, carefully compiled 
from a large number of reliable experiments, gives the tensile 
strength of cement-mortar: 


TABLE XLVII. 

Tensile Strength of Cement-mortar. 


Composiion 
of the 
Mortar. 




Age of Mortar. 



* 

Rosendale. 

Portland. 

Cement 

Sand. 

1 Week. 

1 Month. 

6 Months 

1 Year. 

1 Week. 

1 Month. 

6 Months 

1 Year. 

1 

0 

100 

180 

275 

300 

300 

400 

450 

500 

1 

1 

60 

100 

180 

225 

175 

250 

340 

375 

1 

2 

25 

60 

- 125 

170 

120 

150 

245 

290 

1 

3 

20 

40 

80 

120 

90 

110 

175 

220 

1 

4 

15 

25 

60 

90 

75 

75 

130 

170 

1 

5 

10 

15 

50 

80 

60 

65 

110 

130 

1 

6 

6 

10 

45 

75 

50 

35 

90 

100 


504. Fineness of Sand.—Vicat, in the course of elaborate ex¬ 
periments with limes and mortars in the early part of this century. 


































274 


HIGHWAY CONSTRUCTION. 


established standards for size of grain of what he termed coarse 
sand and fine sand, as follows; coarse sand being such as will pass 
through a sieve of 64 meshes per square inch and be retained on 
one of 289 meshes per square inch, while fine sand will pass through 
a sieve of 289 meshes per square inch and be retained on one of 625 
meshes per square inch. On this definition he ranked the superi¬ 
ority of coarse, mixed, and fine sands with limes according to the 
following schedule: 

For eminently hydraulic limes, 1, fine; 2, mixed; 3, coarse. 

For slightly hydraulic limes, 1, mixed; 2, fine; 3, coarse. 

For fat or quick limes, 1, coarse; 2, mixed; 3, fine. 

It will suffice to say that with cement-mortars much better 
results are obtained when the sand is of the size of grain above 
described and is sharp and clean. 

Mr. Clarke savs that when the sand was formed of a mixture of 
fine and coarse grains nearly as good results were attained as with 
coarse grains alone. 

Before leaving this subject it may be of interest to refer briefly 
to the experiments made at Wilhelmshaven in 1877 by H. Arnold, 
C.E., as published in the Journal of the Hanoverian Architects 
and Engineers* Society for 1883, and from which was found that 
the size of grain and quality of the sand used in Portland-cement 
mortar are important factors in its ultimate strength. With six 
different kinds of substantially clean sands and the same brand of 
-cement mixed into mortar in the proportions of three volumes of 
sand to one volume of cement, the tensile strength after seven days 
ranged from 101 to 243 pounds per square inch, and after twenty- 
eight days from 133 to. 311 pounds per square inch, thus exhibiting 
extremely wide variations, depending largely upon the size and 
roughness of the grains of sand. 

In every instance it was found that a greater strength was de¬ 
veloped with a coarse-grained sand free from very fine particles 
and dust than with a fine-grained sand, both being equally sharp. 
Mr. Arnold also points tb the fact deduced from his experiments, 
that with the same cement but different sands of similar size of 
grain, the cohesion of the mortar may be found to vary consider¬ 
ably, and will probably depend upon the chemical composition of 
the sand. He therefore concludes that in order to obtain satis¬ 
factory results from the cement-mortar used in the construction of 





FOUNDATIONS. 


275 


public works, the quality of the sand available in the particular 
locality should first be taken into careful consideration. 

If no other than a fine sand happens to be available and a given 
strength of the mortar is to be attained at the end of one week, 
experiments should be made to learn whether the proportions of 
sand to cement named in the specifications should be changed, 
since the strength diminishes rapidly with the quantity of sand 
used; and in such an event it may also be advisable to use an 
entirely different kind of cement. It is a necessary condition of 
success in mortar-making that every particle of the sand or “ aggre¬ 
gate be completely covered with the cement or “matrix;” and 
since, when the grains in a given volume are small, the magnitude 
of the total surface to be covered is greater than when the grains 
are large, it follows that fine sand requires a larger proportion of 
cement than coarse sand. Any specification or plan contemplating 
the use of a good coarse sand must, therefore, be altered if fine 
sand alone is used, or else the quality of the work will be im¬ 
paired. 

In support of the foregoing remarks, it has been quite generally 
observed by engineers that when most of our American natural 
cements are mixed entirely with fine sand the jirocess of hardening 
is greatly retarded, even if not entirely prevented; while the same 
cements, when tested neat, exhibit a cohesive strength ranging 
from 50 to 136 pounds in twenty-four hours, thus showing conclu¬ 
sively the effect of admixing the fine material. An instructive in¬ 
stance of this kind was noticed some years ago, when an excellent 
quality of Akron “Star” cement was mixed with very fine sand 
from the Pinnacle pits in the proportion of 2| parts sand to 1 part 
of cement. For several days the mass remained in a plastic state 
in the tin can in which it had been deposited, and upon being 
removed and exposed to the air upon a window-sill for several 
months it displayed very little strength and broke in handling. 
On the approach of cold weather the largest fragment was kept in 
an apartment constantly heated by steam, and after lying undis¬ 
turbed therein for three months pieces could easily be broken off 
with the fingers. At the present time, after having attained an 
age of one year, it is still quite friable and entirely unfit for use. 
Another mass of mortar prepared at the same time from the 
same cement, but with clean, coarse sand, mixed in the proportions 




276 


HIGHWAY CONSTRUCTION. 


of 3 parts of sand to 1 part of cement, indurated promptly and 
exhibited far better qualities. 


TABLE XLVIII. 

Effect of Size of Grain of Sand on Tensile Strength of 

Cement-mortar. 


Denomination of Size of Grains. 

Tensile Strength of Mortar mixed 3 : 1 
with 

Dangast Sand 
after 

Crushed Granite 
after 

7 days. 

28 days. 

7 days. 

28 days. 

Hulled barlev..... 

177 

162 

131 

134 

141 

64 

213 1 

191 

177 

164 

160 

87 

194 

176 

164 

144 

136 

87 

255 

234 

242 

192 

193 

134 

Oatmeal.... 

Standard. .. 

Grass-seed. 

Grit... 

Coarse dust. } 

Fine dust.j 


TABLE XLIX. 

Character of Sieves for Sifting Sands. 


Number of Sieve. 

Number of 
Holes per 
lineal inch. 

Number of 
Holes pet- 
square inch. 

Size of Hole of 
Length of Side 
in inches. 

Diameter of 
Wire in inches. 

1 . 

20 

400 

.03101 

.01899 

2 ... 

30 

900 

.02119 

.01214 

3. 

50 

2500 

.01119 

.00881 


80 

6400 

.00599 

.00051 

5... 

170 

28900 

.00309 

.00279 


505. Portland cement acquires its strength more quickly than 
Rosendale. Both cements, but especially the Rosendale, harden 
more and more slowly as the proportion of sand mixed with them 
increases; and whereas neat cement and rich mortars attain nearly 
their ultimate strength in six months or less, iveak mortars con¬ 
tinue to harden for a year or more. It has also been found that 
after a period of about a year weak mortars often lose in strength 
or tenacity what they may gain in hardness, from the fact of their 











































FOUNDATIONS. 


6 ( ( 


becoming brittle. Specimens of such mortar two years old break 
■very irregularly. Mortars less than one month old are relatively 
weak, and hence the advantage of waiting as long as possible before 
loading masonry structures. Portland-cement mortars are especially 
useful in cases where the structure is necessarily subjected to severe 
strains within so short a period as one week, as frequently happens 
in the case of pavements. 

506. Permeability of Mortar.—The permeability of mortar is 
increased as the proportion of the cement decreases. It increases 
with the coarseness of the sand. Mortars made with a mixture of 
sand of various sizes are relatively non-porous and non-permeable. 
Mortars mixed dry are more permeable than those mixed wet or of 
:a “ normal consistency/ 7 

507. Effect of Frost upon Mortars.—It is a matter of common 
knowledge that ordinary quick-lime mortar which is exposed to the 
action of frost before it has become well set or indurated will thereby 
become greatly injured in its adhesive and cohesive properties; and 
hence where such mortar is used it is customary to suspend all build¬ 
ing operations on the arrival of the cold season. Should, however, 
it be necessary to proceed with the construction, experienced masons 
and builders sometimes make use of a quick-setting cement-mortar 
in place of lime, and cease work when the weather is at all severe. 
It is, therefore, of importance to learn something of the behavior 
of cements under such circumstances. 

The impression seems to prevail quite extensively that cement- 
mortars are not appreciably injured by freezing, and that masonry 
may safely be constructed at any temperature below the freezing 
point at which a man can still work, provided that either brine or 
salt be used instead of fresh water, or that the materials be first 
heated. With regard to the use of brine or salt it may be remarked 
that whether the mortar will be injured thereby or not seems to 
depend principally upon the character of the cement. Most of the 
natural or “ Roman 77 cements suffer a considerable loss of strength 
if mixed with salt water, while the Portland cements do not appear 
to be materially affected. 

Respecting the practice of heating the cement, sand, and water 
before mixing, and then using the hot mortar in cold weather upon 
frosty stones or bricks, or depositing it in icy water, the experiments 
of William W. Maclay, C.E., submitted in 1877 to the American 




278 


HIGHWAY CONSTRUCTION. 


Society of Civil Engineers, show indisputably that such a method 
of treatment is erroneous, and that a great amount of injury is 
effected when heated mortar, even if made of Portland cement, is 
immersed directly in cold water. The tests were all made with 
Burham Portland cement, which, when tested neat at ordinary 
temperature, gave a tensile strength of 278 pounds per square inch 
after seven days. In one series of experiments the ingredients of 
the mortar all had a temperature of about 40 degrees Fahr., and in 
another they were heated to 100 degrees Fahr. These two sets of 
briquettes were kept for seven days in precisely the same manner, 
and were broken on the same day, so that any changes in tempera¬ 
ture during this period would necessarily affect them alike. The 
averages of the tensile strengths acquired show that by first heating 
the ingredients to about 100 degrees, then mixing them in air 
having a temperature of from 13 to 37 degrees, and afterward 
exposing the briquettes for six days to the winter weather, their 
strength in the case of neat cement was only from 7 to 20 per cent 
of that attained when the materials were mixed without heating, or 
with the temperature of the mortar at 40 degrees; and in the case of 
mortar mixed in the proportion of 2 sand to 1 cement, the tensile 
strength of the heated mortar after 28 days was only 30 per cent of 
that reached by the cold mortar at 40 degrees. From these and 
other similar experiments Mr. Maclay concludes that the mixing 
of cement-mortar with highly-heated materials for use above water 
in very low temperatures greatly reduces its normal strength, and 
that for use below icy water its value will thereby be almost entirely 
destroyed. If mortar must be used at all in such weather, it should 
be used cold, and the only condition to be observed is that the 
materials shall be free from frost at the time of using. “ In the 
experiments where the materials were mixed cold and then exposed 
to the winter weather, Portland-cement mortar appeared to set 
without freezing even in as low a temperature as 13 degrees Fahr., 
except when it was windy; but where the briquettes were made of 
hot mortar they invariably froze, as was proven by their becoming 
soft again when the temperature rose/ 7 

Portland cement was found to possess the peculiarity, also 
noticed by many other writers on the subject, of setting in a low 
temperature wherein other varieties of cement will surely freeze. 
No definite limits of this action, however, have yet been assigned. 



FOUNDATION'S. 


279 


Mr. E. Leblanc exposed cakes of Portland-cement mortar to frost 
immediately after mixing and before any setting had occurred, with 
the result that “ they cracked deeply and in part became disinte¬ 
grated, but the detached fragments after being thawed were found 
perfectly hard.” In Mr. Maclay’s experiments none of the Port- 
land-cement briquettes when mixed cold cracked in the slightest 
degree even when exposed to as low a temperature as 11 degrees 
Fahr., and they all became hard after thawing. This seems to be 
the prevailing opinion among engineers. Mr. J. Dutton Steele, 
C.E., in discussing the paper of Mr. Maclay, states that “ cement- 
mortar is not seriously impaired by being laid in frost, as its prop¬ 
erty of setting is simply held in suspense during the time it 
remains frozen.” Gen. Q. A. Gillmore, U.S.A., in his work on 
Beton, etc., remarks that “when the temperature is not much 
below the freezing point during the day, work may be safely carried 
on if care be taken to cover over the new material at night. After 
it has once set and has had a few hours to harden, neither severe 
frost nor alternate freezing and thawing has any effect upon it.” 

In the report of the work performed at the Koyal Testing 
Laboratory of Berlin in 1886 there is an account of a number of 
experiments for ascertaining the effect of frost upon the strength 
of Portland cement, both neat and when mixed into mortar in the 
proportion of 3 parts of sand to 1 part of cement. These tests were 
made in two distinct series, the first one involving only a single 
exposure to frost on and during the sixth day after mixing, while 
in the second series the briquettes were treated as follows: First, 
allowed to indurate for twenty-four hours in the air of a warm 
room; second, exposed for twenty-four hours to a freezing tem¬ 
perature of from + 10 degrees to + 5 degrees Fahr.; third, thawed 
four hours in a warm room; fourth, placed under water until 
tested. 

The experiments were made with six different brands of cement, 
and for each set of briquettes exposed to frost another similarly 
constituted set was kept in temperatures above the freezing point 
to serve as a basis of comparison of tensile strength. Upon test¬ 
ing the frozen and unfrozen samples, it was found that the effect 
of frost varied greatly with the quality of the cement; the loss in 
tensile strength incurred by such freezing ranging after seven days 
from 2 to 22 per cent in the case of neat cement, and from 3 to 24 



280 


HIGHWAY CONSTRUCTION. 


per cent in the case of the mortar mixed as above described; also 
ranging after 28 days from 2 to 12 per cent in the case of neat 
cement, and from 1 to 33 per cent in the case of the mortar. It 
should be noted particularly that the foregoing results were de¬ 
rived when pure, clean, and standard materials only were used. On 
the other hand, where the cement was adulterated with 30 per cent 
of pulverized slag from a blast-furnace the loss in strength by 
freezing was much greater than above given, especially in the case 
of the mortar. After seven days this loss ranged from 6 to 62 per 
cent, and after 28 days from 21 to 41 per cent, standard sand hav¬ 
ing been used. 

Other interesting experiments with regard to the effect of frost 
on Portland-cement mortar were carried out early in 1886 at Ham¬ 
burg, Germany, by Mr. Moeller, C.E., and an account thereof is 
contained in the Deutsche Bauzeitung for November 17, 1886. 

The results showed that Portland-cement mortar, whose time of 
setting is lengthened by the addition of sand or lime, or both, suf¬ 
fers severely in loss of tensile strength by the action of frost, and 
tnat such loss becomes greater as the proportion of sand or lime is 
increased; further, that a quick-setting Portland cement will indu¬ 
rate in spite of the frost, provided that it be protected therefrom 
for two days after having been tempered, and that it be as dry as 
possible before exposure to the cold. It was also found that the 
mixing of such materials with brine renders the mortar more capa¬ 
ble of resisting the influence of frost, and that this statement like¬ 
wise holds true for slow-setting compounds, such as 1 part of cement, 
1 part of lime, and 3 parts of sand. Mortars thus prepared and 
mixed with fresh water instead of brine, and kept for two days at 
a temperature of -f 41 degrees Fahr., and then exposed to the frost, 
lost nearly all strength, so that even after four months pieces could 
easily be broken off from the briquettes with the fingers; whereas 
when tempered with strong brine their strength after seven months 
was about fourteen times greater. Accordingly, if the mortar can 
be kept from freezing for a few days by the use of salt or brine, 
so as to allow the setting to take place, much benefit is sure to be 
derived. 

It may also be deduced from these experiments that when it 
becomes absolutely necessary to lay masonry in freezing weather, 
quick-setting Portland cements, mixed with small proportions of 



FOUNDATIONS. 


281 


sand and water, should alone be employed; and when a satisfactory 
quality of work is expected or required, the use of brine or salt 
should be resorted to, as well as the protection of the newly-laid 
masonry at night by means of adequate coverings. In case, how¬ 
ever, that the temperature is lower than 23 degrees Fahr. even 
these precautions will not prevent more or less damage. 

Under such circumstances, moreover, it is self-evident that the 
stones or bricks should be free from snow or ice and as dry as prac¬ 
ticable; also that all the materials, including the sand and cement, 
be free* from frost by being kept at a temperature above the freez¬ 
ing point for some days before being used in the work. The safest 
rule, however, is to cease operations with mortars of any kind dur¬ 
ing the prevalence of frost. 

In a paper read before the American Society of Civil Engineers 
in July, 188G, its author, Alfred Noble, C.E., states that “ in the 
construction of the lock at the St. Mary’s Falls Canal, the laying 
of masonry was discontinued about October 20 of each year, on 
account of the frequent recurrence of freezing weather. On the 
last day of the work done in 1877 mortars made of Portland 
cement and of a good quality of American natural cement were 
used in adjoining portions of the same wall. Both mortars were 
mixed in the proportions of 1 cement to 1 sand, and the masonry 
was laid during a light rain. The following spring the surface of 
the Portland-cement mortar was sound, showing perfectly the 
marks of the rain-drops, while the natural-cement mortar was dis¬ 
integrated to a depth of three or four inches.” Mr. Noble also 
mentions a few other cases where Portland-cement mortar was used 
in laying masonry during very cold weather without affecting the 
subsequent induration of the mortar noticeably. The inference to 
be drawn from his paper is that if it becomes imperative to use 
mortar in freezing weather, Portland cement should be used. 

Similar effects of frost were also noticed by Mr. Francis Colling- 
wood, C.E., on the Rosendale-cement mortars, mixed in the pro¬ 
portion of 2 sand to 1 cement, used for the masonry of the East 
River Bridge, since he states that “ the tops of the various pieces 
of masonry were always gone over carefully in the spring. The 
concrete which had been put in late would usually be found disin¬ 
tegrated to a depth of from one to four inches, but below this it 
was found sound. The rule seems to be that it was unsound only 





HIGHWAY CONSTRUCTION. 


282 


so far as it was exposed alternately to freezing and thawing; and 
wherever it had taken a set before freezing, and had not been 
thawed out for some time, it was sound.” The experience of Mr. 
George S. Morison, C.E., with cements as given in his discussion 
of Mr. Noble’s paper, was in full accord with what was therein 
stated, and in his extensive practice as a designer and builder of 
large bridges he uses Portland cement exclusively in all places 
where the mortar is liable to freeze before setting. Mr. Eliot C. 
Clarke, C.E., also mentioned that in experimenting with concretes 
of Rosendale and Portland cements which had been exposed to the 
weather for three years he found that the former was injured and 
disintegrated from year to year, while the latter were not affected 
at all. 

Recent expressions of opinion from many other excellent au¬ 
thorities respecting the action of frost on cement-mortars are to 
the same effect as above recited. It is generally agreed that the 
freezing of freshly-prepared cement-mortar will not destroy its 
capacity to harden after becoming thawed, but exactly how much 
its cohesive and adhesive strength will thereby become impaired 
does not appear to be definitely known; neither is the effect of re¬ 
peated freezing and thawing very clearly pointed out. In our 
winters it frequently happens that water freezes in the shade, while 
at the same time ice melts in the sunlight, and hence under such 
circumstances in a wall facing south a slow-setting mortar in the 
face will be alternately frozen and thawed, while that in the rear 
will continue to remain frozen. This condition of the work can¬ 
not fail to be prejudicial to its ultimate strength, and manifestly 
demands that a strong and quick-setting mortar be used if the lay¬ 
ing of masonry be continued in freezing weather. Numerous in¬ 
stances of failure of walls and abutments built in winter may be 
cited which are fairly attributable to the thawing out of the frozen 
mortar after the warm weather has set in, whereby it becomes 
almost as soft as when first mixed. In such cases the thawed 
mortar acts rather as a lubricant than as an efficient binding mate¬ 
rial, and if the structure is then subjected to lateral forces of con¬ 
siderable magnitude, deformation or failure is sure to follow unless 
a very wide margin of safety has been allowed in the design. 
When, however, the dimensions are fixed with reference to econ¬ 
omy and the use of ordinarily good materials and workmanship, as 



FOUNDATIONS. 


283 


generally happens, the action of frost becomes a very serious factor 
in the stability and durability of the work, and therefore care 
should be taken in the proper selection of the cement. It must 
always he remembered that frozen cement-mortar will not set so 
long as it remains frozen, and that when it becomes thawed it is 
simply in the condition of material freshly mixed, which, while in 
that state, imparts no more strength to the structure than sand, 
ashes, mud, or other inert matter. 

A rather close observation for a number of years of the effects 
of frost on Buffalo and Akron cement-mortars, mixed in the pro¬ 
portion of two sand to one cement and three sand to one cement, 
leads to the conclusion that such mortars entirely disintegrate to a 
depth of several inches in exposed joints of masonry laid in cold 
weather; also that when used as coatings or renderings of rough 
stone surfaces a flaking thereof occurs by frost which leads to 
rapid disintegration. If it is imperative that masonry be built in 
freezing weather, a quick-setting Portland cement-mortar should 
be used, instead of such as is prepared with natural cements; 
also that even when Portland cement is used with brine, work 
should be suspended when the temperature is lower than 25 degrees 
Fahr., if good results are to be expected; and finally, smaller pro¬ 
portions of sand shoud be used than during the prevalence of higher 
temperatures. 

508. The standard of tensile strength required by German 
engineers of Portland-cement mortar, prepared by mixing one unit 
of weight of cement with three like units of normal sand, and 
four tenths of such a unit of clean fresh water, and tested after an 
exposure of one day in air and twenty-seven days in water, is 227 
pounds per square inch and a resistance to compression of 2300 
pounds per square inch. 

509. English Specifications for Portland Cement.— The follow¬ 
ing is a summary of the specifications used by Mr. Henry Faija, 
an accepted English authority: 

Fineness .—To be such that the cement will pass through a 
sieve having 625 holes (25 2 ) to the square inch, and leave only 10 
per cent residue when sifted through a sieve having 2500 holes 
(50 2 ) to the square inch. 

Expansion or Contraction .—A pat made and submitted to 



284 


HIGHWAY CONSTRUCTION - . 


moist heat and warm water at a temperature of about 100 degrees 
Fahr. shall show no sign of ‘blowing in twenty-four hours. 

Tensile Strength .—Briquettes of slow-setting Portland, which 
have been gauged, treated, and tested in the prescribed manner, to 
carry an average tensile strain, without fracture, of at least 176 
pounds per square inch at the expiration of three days from gaug¬ 
ing; and those tested at the expiration of seven days to show an 
increase of at least 50 per cent over the strength of those at three 
days, but to carry a minimum of 350 pounds per square inch. 

For quick-setting Portland at least 176 pounds per square inch 
at three days, and an increase at seven days of 20 to 25 per cent, 
but a minimum of 400 pounds per square inch. Very high 
tensile strengths at early dates generally indicate a cement verging 
on an unsound one.” 

510. Data for Estimates.—The following data will be found 
useful in estimating the amounts of the different ingredients neces¬ 
sary to produce any required quantity of mortar: 

One barrel of lime (230 pounds) will make about 2^ barrels (0.3 
cubic yard) of stiff lime-paste. One barrel of lime-paste and three 
barrels of sand will make about three barrels (0.4 cubic yard) of 
good lime-mortar. One barrel of unslaked lime will make about 
6.75 barrels (0.95 cubic yard) of one to three mortar. 

A barrel of Portland cement weighs 400 pounds gross, or about 
375 net. Hudson River Rosendale weighs 300 pounds net per bar¬ 
rel. Western Rosendale weighs 265 pounds net per barrel. 

A barrel of Rosendale, as packed at the manufactories on the 
Hudson will measure from 1.25 to 1.40 barrels if measured loose. 
A barrel of Western Rosendale will make about 1.1 barrels if 
measured loose. A commercial barrel of Portland will make about 
1.2 barrels if measured loose. 

One cubic foot of dry cement (shaken down but not compressed) 
mixed with 0.33 cubic foot of water will give 0.63 cubic foot of stiff 
paste. One barrel (300 pounds) of finely ground Rosendale cement 
will make from 3.70 to 3.75 cubic feet of stiff paste; or 79 to 83 
pounds of cement-powder will make about one cubic foot of stiff 
paste. Volume for volume, Portland will make about the same 
amount of paste as Rosendale; or 100pounds of Portland will make 
a cubic foot of stiff mortar. 

511. Machine-mixed mortars and concretes are superior to hand- 




FOUNDATIONS. 


285 


mixed. In hand-mixing the first drawback is the liability to error 
in measuring out correct and uniform proportions of prescribed 
materials. Mortar men make mistakes which generally happen to 
be against the proper proportions of cement. The quantity of sand 
will also vary according to whether it is measured in wet or dry 
condition, packed or loose. Next the workmen fail to intermix the 
cement and sand thoroughly before adding the water—an important 
point. Again, they will ease up on the labor required to mix all 
well together after applying water, and to facilitate the operation 
will over-dose the water. A further error occurs in assuming that 
all barrels of cement contain equal quantities. The necessity of a 
close supervision will be recognized in these particulars. 

512. Specifications for Concrete (Boston).—The American cement- 
concrete shall be made of one part of American hydraulic cement, 
two parts of clean, sharp sand, and five parts of clean broken stone 
or screened gravel-stones by measure. 

The Portland-cement concrete shall be made of one part Port¬ 
land cement, three parts of clean, sharp sand, and seven parts of 
clean broken stone or screened gravel-stones by measure. 

The stone for the concrete shall be free from clay, dirt, or other 
objectionable material; no stone shall be larger than 2% inches and 
but very few less than i inch in their greatest dimensions. 

The mixing shall be done in proper boxes, in a manner satisfac¬ 
tory to the engineer; and after the materials are wet the work must 
proceed rapidly until the concrete is in place and is so thoroughly 
rammed that water flushes to the furface and all the interstices be¬ 
tween the stones are entirely filled with mortar. The surface of 
the concrete foundation must be floated and made exactly parallel 
with the crown of the pavement to be laid, and must be suitably 
protected from the action of the sun and wind until set. It shall 
be allowed to set a sufficient time, to be determined by the engin¬ 
eer, before walking over or working upon it shall be allowed. 

513. Specifications for Concrete (Berlin).—The concrete is to be 
prepared from a mixture of cement and sand or a mixture of cement, 
sand, and broken granite or limestone. In making it at least one 
barrel of cement in the standard proportion of 180 kilos gross or 
70 kilos net weight is to be used with one cubic meter of sand or of 
sand and stone. The proportions of sand and broken stone are to 
be determined in each case by the inspector. If in exceptional 




28G 


HIGHWAY CONSTRUCTION. 


cases a greater proportion of cement is employed to obtain quicker 
setting, a corresponding payment will be made for each barrel used, 
as given in the schedule of prices. 

The cement is to be weighed whenever the inspector desires. 
In order that the proportions ma} r exactly conform to the specifica¬ 
tions, the sand or mixture of sand and stone is to be measured in 
boxes holding exactly one half or one cubic meter. 

The mixing is done on a platform that must be 30 centimeters 
(11.8 inches) larger all around than the bottom of the measuring- 
boxes. The sides are to be j^ovided with strips to prevent the 
falling of the material. In order to insure regular work at least 
five mixing-boards are to be set up at each place fo working. 

Sand and cement are to be twice mixed dry before water is 
added. After the addition of the water the mass must be immedi¬ 
ately worked to a stilf condition. During the preparation of the 
concrete, all the foreign bodies in the cement or sand are to be 
carefully removed. If, during the process of mixing, a portion of 
the concrete, of sand or stone, falls from the platform, it must not 
be again added to the mass and used in the concrete, but must 
be removed. 

Laying the Concrete .—In order to insure the exact formation 
of the concrete foundation, a series of templates are to be laid on 
the road-bed from 4 to 5 meters apart and parallel to the axis of 
the street. The greatest care must be taken to have these templates 
at the proper height, and all out of alignment must be immedi¬ 
ately removed. 

When the road-bed has been finally brought to the proper grade 
the concrete is to be laid between the templates and thoroughly 
tamped and worked into a profile corresponding to that of the 
finished street surface. 

Use of the Concrete after its Preparation .—While the concrete 
is setting, it is to be sprinkled with water so that the surface is 
continually moist, and as long as it remains soft the work must be 
protected by suitable guards from intruders. 

No concrete shall be prepared at a temperature below 2 degrees 
Keaumur (36J degrees Fahr.). Concrete just laid is to be pro¬ 
tected for two days, when frost begins, by a covering of mats or 
bundles of straw. 

The foundation must have exactly the same profile as the upper 



FOUNDATIONS. 


287 


surface of the finished pavement is to receive. It is especially 
necessary that the surface be free from all inequalities, elevations 
as well as depressions. Work must not begin on the construction 
of the foundation until the inspector has definitely stated that the 
work on the roadbed has been finished in the manner prescribed 
in the regulations. 

514. Specifications for Concrete (New York). —One part of 
American cement, equal to the best quality of freshly burned 
Rosendale cement, two parts of clean, sharp, washed sand, free 
from clay, to be thoroughly mixed dry and then made into mortar 
with the least possible amount of water; to this shall be added 
three parts of sound stone, broken with a hammer, the largest of 
which will pass through a 2-inch ring, the broken stone to be wet 
before being added to the mortar. The whole mass shall then be 
shoveled over until it is thoroughly mixed before it is put in place; 
it shall then be put in place and rammed until it is thoroughly 
compacted and has a clean mortar surface. 

The whole operation of mixing and laying each batch will be 
jierformed as expeditiously as possible, by the employment of a 
sufficient number of skilled men. 

The upper surface will be made exactly parallel with the pave¬ 
ment when laid, and, if necessary, will be protected from the action 
of the sun and wind until set. 

No concrete will be allowed to be used which has been mixed 
more than three hours. 

The concrete shall be laid to a depth of 6 inches. 

515. Concrete for Foundations, as used in Paris. —The propor¬ 
tions by bulk are: 

Cement 

Sand... 

Gravel. 

Water.. 

or one of cement to ten of sand and gravel. 

The concrete is mixed on a large mortar-board, the mixers mov¬ 
ing the board ahead as the work advances, and never being more 
than a few feet from the spot where the concrete is to be placed. 

A square wooden form is placed on the mortar-board; into this 
is dumped successively, in the order named, 2 barrows of gravel, 


1 part 
4 parts 
6 “ 

1 * “ 








288 


HIGHWAY CONSTRUCTION". 


\ sack of cement, 1 barrow of gravel, \ sack of cement, 2 barrows 
of sand. The form is then removed, and the mass turned over dry 
with the shovel by two men working side by side. It is then 
turned a second time by the two men, while a third sprinkles on 
the water from a pot. The mass is then turned over a third time, 
and shoveled from the board directly into place. 

This concrete sets quickly, and every evening the surface of that 
laid during the day is covered with a thin coat of pure cement. 

516. Specifications for Preparation of Roadbed. —The subsoil 
or other matters (be it earth, rock, or other material) shall be 
excavated and removed to a depth of inches below the top line 
of the proposed pavement. Should there be any spongy material, 
vegetable or other objectionable matter, in the bed thus prepared, 
all such material must be entirely removed, and the space filled 
with clean gravel or sand carefully rammed. 

The roadbed shall be truly shaped and trimmed to the required 
cross-section and grade, and rolled to ultimate resistance with a 
roller weighing not less than ten tons; such portions of the road¬ 
bed as cannot be reached by the roller shall be consolidated with 
hand rollers or tampers. 

Note .—The employment of ashes, garbage, or other objectionable 
matter should not be permitted for filling on the streets of cities 
and towns. 

Rock shall be excavated to a depth of 2 feet below the level of 
the finished grade, and the space so excavated shall be refilled to 
subgrade level with gravel, steam ashes, or other approved material, 
and thoroughly consolidated. 



CHAPTER X. 


RESISTANCE TO TRACTION. 

517. The resistance to traction on highways is occasioned (1) by 
the want of uniformity in the surface of the road, the weight of the 
load having to be lifted over the projecting points and out of hol¬ 
lows and ruts, thus diminishing the effective load which the horse 
may draw to such as it can lift. 

(2) The want of strength of the roadbed itself, however free 
its surface may be from asperities or cavities, if its substructure 
be of such a nature that it will yield to the pressure of the wheels, 
adds another impediment to the movement of a load over it, with 
the additional disadvantage that while the horse is endeavoring to 
lift the load from a cavity or hollow, the fulcrum, which in the 
first case was supposed to be fixed and rigid, is in the latter yielding 
and variable, subjecting the horse to the constant effort of lifting, 
instead of simply drawing. 

518. Want of Uniformity in the Surface. —The power required 
to draw a wheel over a stone or any obstacle, such as S in Fig. 36, 
may be thus calculated. Let P represent the power sought, or 



that which would just balance the weight on the point of the 
stone, and the slightest increase of which would draw it over. 






290 


HIGHWAY CONSTRUCTION. 


This power acts in the direction CP with the leverage of BC 
or DE. Gravity, represented by W, resists in the direction CB 
with the leverage of BD. The equation of equilibrium will be 
P x CB = W X BD, whence 


T BD _ W VCD 2 - BC 2 
CB CD - AB 


Let the radius of the wheel = CD = 26 inches, and the height 
of the obstacle = AB = 4 inches. Let the weight W — 500 
pounds, of which 200 pounds may be the weight of the wheel and 
300 pounds the load on the axle. The formula then becomes 


P = 


500 


|/676 - 484 
~26 — 4 


= 500 


13.85 

22 


= 314.7 pounds. 


The pressure at the point D is compounded of the weight and 
the power, and equals 

f^CD 25 

W 7775 = 500 X — = 591 pounds, 

C Jj ZZ 


and therefore acts with this great effect to destroy the road in its 
collision with the stone, in addition there is to be considered the effect 
of the blow given by the wheel in descending from it. For minute 
accuracy the non-horizontal direction of the draught and the 
thickness of the axle should be taken into account. The power 
required is lessened by proper springs to vehicles, by enlarged 
wheels, and by making the line of draught ascending. 

519. Resistance of Penetration. —This resistance is that of a 
medium distributed over the submerged portion of the circum¬ 
ference of a wheel, in advance of the perpendicular line drawn 
from the centre of the wheel to the plane of the road. The 
following investigation furnishes a formula for calculating, with 
sufficient degree of accuracy, the resistance of gravel, loose stones, 
soft earth, or clay. 

Let A OB, Fig. 37, be a wheel drawn over the horizontal 
surface CDE of the road, in the direction OF, and let the road 
be of such a consistency that the wheel penetrates to the depth 












RESISTANCE TO TRACTION. 


291 


DB below the surface, leaving a track BG behind it. The arc 
BC is the submerged portion of the circumference, and it may be 
assumed to be identical with the chord of the arc BC. Now the 
resistance is distributed over the surface BC, and it may be taken 



Fig. 37. 

as acting on this surface perpendicularly to the plane of the road, 
or vertically and directly opposed to the gross weight, consisting 
of the weight of the wheel and the load upon it. To simplify the 
investigation, let it be supposed that the upper portion of the road 
is homogeneous, as clay or sand; then the resistance to penetra¬ 
tion is nothing at the surface, and it increases as the depth; and 
the upward resistance along the line of submersion, BC, is a 
maximum at B and it vanishes at C, and the varying intensity of 
the graduated pressure may be represented by an isosceles triangle, 
of which the centre of gravity, H, situated at one thiid ot its length, 
BH, from the base, B, is also the centre of resistance, and therefore 
also the centre of pressure under the load; and the radial line OH 
is the resultant of the pressure of the load, measured in force and 
direction by the vertical 01, and the tractive force, measured by 
the horizontal line HI or OK. But the vertical 01 may be taken 
as equal to the radius OB, and the horizontal HI may be taken, 
as one third of the semi-chord of submersion CD ; whence the 

proportion 

Load : tractive force :: OB : CD :: radius of wheel : j semichord; 












292 


HIGHWAY CONSTRUCTION. 


and the resistance to traction is equal to the product of the load 
by the third of the semichord divided by the radius of the wheel. 

But the length of the semichord CD may be more easily deter¬ 
mined by calculation from the measured depth of submersion DB. 
It is equal to the square root of the products of the segments into 
which the diameter AB is divided by the plane of the road CDE, 
or to VAlJx DB ; and the whole of the calculations is embraced 
by the equation 


Tractive force OK = 



W VAD x BD 
OB 



The work done in compressing the material of the road is 
easily indicated diagrammatical^ by supposing the wheel to advance 
through a sjjace equal to the semichord CD, or the length of the 
submersion. Thus, in Fig. 38, the wheel AB is supposed to roll 



forward and to occupy the position A'B'. The work done in 
compressing the road is proportioned to the four-sided area 
BCC'B comprised between the circumferential segments BC and 
B'C', and this area is, by the properties of the circle, equal to the 
original rectangular area BDCB'. 

Now, suppose a wheel ABA, Fig. 39, of larger diameter with 
the same gross weight, to travel over the same surface. It is 
obvious that, if it could sink to the same depth, db, as that for the 
smaller wheel, the length of immersion, dc , Avould be increased, 
and the rectangle, db x do, representing work, would be greater 


















RESISTANCE TO TRACTION. 


293 


than that performed by the smaller wheel in the first example. 
Such a supposition cannot be admitted: the depth of immersion, 
clB, for the larger wheel, must be less than that, db, for the smaller 
wheel, though the length of immersion dC, must be greater than that 
clc, for the smaller wheel, but not so much greater as if the wheel 
were sunk to the first depth, db. 

In fine, larger wheels sink less but spread more into the surface 
than the smaller wheels, in such proportion that the area of the 
rectangle representing work of submersion is constant for all sizes 
of wheels. In this instance, accordingly, the rectangle db X clc = 
the rectangle dB x dC. 

It might be thought that, on this principle of the constancy of 
the work of submersion, in a soft road, the resistance to traction 
must be the same for all diameters of wheels. But, as the rect¬ 
angle of work is spread over a longer space, clC, for the larger 
wheel, than the space, clc, for the smaller wheel, it follows, on the 
contrary, that the resistance or force of traction varies in some 
proportion inversely as the diameter, being less as the diameter is 
greater. This conclusion accords with experience; but though the 
actual law of variation may not be strictly deducible in the line of 
reasoning here traced, it is nevertheless useful to carry the reason¬ 
ing to its logical conclusion. Let a and A be the diameters respec¬ 
tively of the smaller and the larger wheels, b and B the depths of 
immersion, and c and C the lengths of immersion, or dc and Dc, 
respectively. As already stated, the areas of immersion are equal 
to each other, or 

bc = BC. .(2) 

Also, the values of c and C are, by the properties of the circle, ex¬ 
pressible by the products Vab and VAB, for all cases that need 
occur in practice; and, by substitution in the equation (2), 


bVab = BVAB) . . 



and, squaring both sides, 


ab 3 = AB Z . 


( 4 ) 







294 


HIGHWAY CONSTRUCTION. 


Finally, extracting the cube root of each side of this equation (4), 
the equation (5) is obtained, 

bVa = BV2, .(5) 


which may be developed into the proportion 

b : B:: VA : a\ .(6) 

showing that the depth of immersion varies as the cube root of the 
diameter. But, as be — BC, and b: B: : C: c, then, 

C : c :: VA : Va, .(7) 

showing that the length of immersion is as the cube root of the 
diameter. It has already been seen that the force of traction is as 
the length of immersion; therefore, finally, 

520. The circumferential or rolling resistance of wheels to 
traction on a level road is inversely proportional to the cube root 
of the diameter. 

On this principle of resistance, it follows that, to reduce the 
rolling resistance of a wheel one half, for instance, the diameter 
must be enlarged to eight times the primary diameter. 

>The deduction of M. Morin, that the resistance varies simply in 
the inverse ratio of the diameter of the wheel,—so that, for exam¬ 
ple, a wheel of twice the diameter would only incur half the resist¬ 
ance,—has been generally accepted. But this deduction is not 
supported by the foregoing analysis of forces, and there is good 
reason for renouncing it, in the more recent experiments of M. 
Dupuit. He placed model wheels or rollers of various diameters at 
the summit of an inclined plane, succeeded by a horizontal plane, 
on which they rolled down by the force of gravity and arrived at a 
state of rest after having expended the energy acquired in falling 
through the height of the plane. From these and other experi¬ 
ments he drew the following deductions: 

On macadamized roads in good condition, and on uniform sur¬ 
faces generally, 

(1) The resistance to traction is directly proportional to the 
pressure. 







RESISTANCE TO TRACTION. 


295 


(2) It is independent of the width of the tire. 

(3) It is inversely as the square root of the diameter. 

(4) It is independent of the speed. 

M. Dupuit admits that on paved roads which give rise to con¬ 
stant concussion, the resistance increases with the speed, whilst it 
is diminished by an enlargement of the tire up to a certain limit. 

The resistance produced by the hollows between the stones of a 
pavement is of a different character. According to M. Gerstner, 
the resistance arising from such a surface is directly proportional 
to the load, to the square of the velocity, and to the ratio of the 
width of the cavity to the radius of the wheel, and inversely pro¬ 
portional to the width of the paving-stones. 

521. Friction.—The resistance of friction arises from the rub¬ 
bing of the wheels against the surfaces with which they come in 
contact, and will always exist. The friction of surfaces is variable, 
and can be determined only by experiment. Friction of the axles 
and resistance of the air are causes of resistance to motion but 
their consideration may be neglected, as their effects are constant, 
and independent of the imperfections of the road. 

522. Many experiments have been made at various times to 
ascertain, in functions of the quality and condition of the road-sur¬ 
faces, the measure of the tractive force, or the force required to 
overcome the resistances which oppose themselves to the movement 
of a vehicle along horizontal roads of different degrees of smooth¬ 
ness and hardness and covered with different materials. 

Table L presents the results of those experiments. The frac- 


TABLE L. 

Resistance to Traction on Different Road-surfaces. 

(Rudolf Hering). 


Character of Road. 

Resistance 
in Terms of 
-Load. 

Pounds 
per ton. 

Velocity. 

Authority. 

Sand . . 

A 

448 

Pace 

Bevau 

Snnrir rnfl.d... 

187 

3' to 12' per sec. 
Pace 

Morin 

flra vpI /lnnsp.1.. 

1 -5 

1 

320 

Bevau 

“ (A in thick). 

tV 

224 

i i 

Morin 

“ (common road). 

“ (Toad).. . . 

1 u 

1 

• T6 

1 

140 

86 

( ( 

3’ per sec. 

12' per sec. 

Macheil 

Rumford 

n a 


90 

< c 



























29G 


HIGHWAY CONSTRUCTION, 


Resistance to Traction on Different Road-surfaces— Continued. 


Character of Road. 


Gravel (hard rolled). 

Turf (wet). . 

“ (dry and hard). 

<t €i <i ^ 

Earth (ordinary road). 

Earth (dry and hard). 

Clay (hard). 

Cobblestones (ordinary).... 

a a 

“ (good, 34 in.). 

cc a a 

Macadam (little used). 

“ (bad). 

“ (old). 

“ (ordinary). 

iC IC 

Macadam (good, slightly 

muddy). 

Macadam (best French).... 
Macadam (very hard and 

smooth).. 

Macadam (best). 

it ii 

t< a 

€C (< 

Belgian block (ordinary)... 
Bel. block (Boulev., Paris). 
“ “ (good). 

(C ti a 

“ “ (well laid).. 

“ “ (good). 

Granite block (ordinary)... 

“ ** (good). 

i€ a << 

“ ** (good Loud). 

Planked roadway. 

Asphalt. 

Granite tramway. 

Iron tramway. 

Sleighs on snow 3 in. thick 
f in. runner, temperature 
26° Fahr. 


Resistance 
in Terms of 

Pounds 

Load. 

per ton. 


75 

i 

280 

tV 

124 

St 

90 

TO 

224 


101-75 

l 

dd 

112 

i 

280 

xV 

140 

l 

T t 

150 

l 

3(1 

75 

1 1 

Id S3 

140-97 

i 

160 

St 

90 

St 

90 

aV 

64 

l _ l 

3d 5T 

75-41 

tt 

45 

tt 

45 

St 

64 

Tt 

50 

tV~(tV 

48-37 

iWd 

52-30 

1 

To 

56 

l _ l 

To 6 6 

50-34 

1 

3d 

75 

60 

37 

dV 

35 

tV~fV 

50-26 

St 

90 

TT 

132 

6d 

45 

dd 

36 

-1-1 

Td 5 7 

56-40 

Tdd 

17 

1 

14 

T3dTdd 

d£d 

11 

l 

3d 

75 


Velocity. 


Authority. 


Pace 


Pace 

it 


Trot 

Pace 

Trot 

Pace 


Pace 


Trot 

Pace 


Trot 

Pace 


Pace 


Trot 

Pace 


Trot 

Pace 


j Bevan 
( Minard 
Morin 

<i 

Bevan 

<< 

Morin 

Bevan 


Kossack 

U 

Morin 
Gordon 
Navier 
j MacNeil 
( Perdon’t 
Kossack 

Morin 

Navier 

MacNeil ; 
Rumford 

t i 

Gordon 

Morin 

MacNeil 

Navier 

Rumford 

i i 

MacNeil 
Morin 
( Perdon’t 
■ Poncelet 
( Minard 
Rumford 

a 

Gordon 

Morin 

Gordon 


Ci 





































































RESISTANCE TO TRACTION. 


297 


.tions which are generally rounded off, indicate the part of the whole 
weight which is equivalent to the resistance of drawing it on a 
level road. An examination of this table will clearly show the great 
economy in horse-power by using the hardest and smoothest ma¬ 
terial for road-coverings. For instance, if 1 horse can just draw a 
load on a level road on iron rails, it will require 1^ horses to draw it 
on asphalt, 3^ on the best Belgian-block pavement, 7 on good 
cobblestone pavement, 1.3 on bed cobblestone, 20 on an ordinary 
earth road, and 40 on a sandy road. 

523. The following deductions are from the experiments of 
MM. Dupuit and Morin: 

1st. The resistance to traction on uniform smooth surfaces is 
directly proportional to the load, and inversely as the square root of 
the diameter of the wheels. 

2d. It is independent of the width of the tire when this quantity 
exceeds 3 or 4 inches. 

3d. It is independent of the speed. 

4th. On paved surfaces which give rise to constant concussion, 
it increases with the speed. 

5th. Upon soft roads of earth or sand or turf, or roads fresh 
and thickly gravelled, the resistance to traction is independent of 
the velocity. 

6th. At a walking pace, the resistance is the same, under the 
same circumstances, for vehicles with springs and for vehicles with¬ 
out springs. 

7th. The destruction of the road is, in all cases, greater as the 
diameter of the wheels is less, and it is greater in vehicles without 
than with springs. 

524. The comparative ease of draft on various surfaces is largely 
influenced by the amount of foothold afforded, and it may be 
doubted if dynamometer experiments, however carefully made, are 
altogether conclusive. The tractive force is influenced by the di¬ 
ameter of the wheels, the friction of the wheels on the axles, and the 
speed, as well as by the resistance of the road surface; and these 
must be hll taken into account to obtain accurate results. Recent 
experiments on London and Paris street pavements gave the fol¬ 
lowing results, speed 2 to G miles per hour: 



298 


HIGHWAY CONSTRUCTION. 


TABLE LI. 

Tractive Force on a Level. 


Surface. 

Pounds per ton. 

London. 

Paris. 

Macadamized. 

40.7 to 44.29 
39.0 “39.32 
33.62 “ 36.03 
26.2 “27.00 

32.12 to 39.38 

Asphalt . 

Wood. 

33.44 to 39.16 
35.20 

Granite. 



525. Gravity. —The grade of the road, or the quantity by which 
it differs from a level. The grade resistance is due to the force of 
gravity, and is the same on both good and bad roads, and unlike the 
others may be determined from the laws of mechanics, whilst the 
former are determinable entirely by experiment on the road in 
question. The resistance due to gravity on any incline in ]3ounds 


per ton = 


2240 


rate of grade’ 


TABLE LII. 

Resistance due to Gravity on Different Inclinations. 


Grade 1 inch. 

20 

30 

40 

50 

60 

70 

80 

90 

100 

200 

300 

400 

Rise in feet per mile. 

264 

176 

132 

105 

88 

75 

66 

58 

52 

26 

17 

13 

Resistance in lbs. per ton 

112 

744 

56 

45 

38 

32 

28 

25 

22 

Hi 

74 

54 


526. The additional resistance caused by inclines may be inves¬ 
tigated in the following manner: Suppose the whole weight to be 
borne on one pair of wheels, and that the tractive force is applied 
in a direction parallel to the surface of the road. 

Let AB in Fig. 40 represent a portion of the inclined road, C 
being a vehicle just sustained in its position by a force acting in the 
direction CD. It is evident that the vehicle is kept in its position 
by three forces; namely, by its own weight W acting in the vertical 
direction CF, by the force F applied in the direction CD parallel 
to the surface of the road, and by the pressure P which the vehicle 
exerts against the surface of the road acting in the direction CB 
perpendicular to the same. To determine the relative magnitude 



































RESISTANCE TO TRACTION. 


299 


of these three forces, draw the horizontal line A G and the vertical 
one BG ; then, since the two lines CF and BG are parallel and are 



both cut by the line AB , they must make the two angles CFE and 
ABG equal; also the two angles CFFand AGB are equal; there¬ 
fore the remaining angles FCE and BA G are equal, and the two 
triangles CFE and ABG are similar. And as the three sides of the 
fdrmer are proportional to the three forces by which the vehicle is 
sustained, so also are the three sides of the latter; namely, AB or 
the length of the road is proportional to W, or the weight of the 
vehicle; BG, or the vertical rise in the same, to F, or the force re¬ 
quired to sustain the vehicle on the incline; and AG, or the hori¬ 
zontal distance in which the rise occurs, to P, or the force with 
which the vehicle presses upon the surface of the road. Therefore 


W:AB::F: GB, 


and 


W : AB :: P : AG. 

And if to A G such a value be assigned that the vertical rise of the 
road is exactly one foot, then 



W 

AB 


W 

VAG' + 1 


W. sin A, 











300 


HIGHWAY CONSTRUCTION". 


and 


W.AG _ W.AG 
AB ~ VAG' + l 


W. cos A, 


in which A is the angle BA G. 

527. To find the force requisite to sustain a vehicle upon an 
inclined road (the effects of friction being neglected), divide the 
weight of the vehicle and its load by the inclined length of the 
road, the vertical rise of which is one foot, and the quotient is the 
force required. 

528. To find the pressure of a vehicle against the surface of an 
inclined road, multiply the weight of the loaded vehicle by the hori¬ 
zontal length of the road, and divide the product by the inclined 
length of the same; the quotient is the pressure required. 

529. The force with which a vehicle presses upon an inclined 
road is always less than its actual weight; the difference is so small 
that, unless the inclination is very steep, it may be taken equal to 
the weight of the loaded vehicle. 

530. To find the resistance to traction in passing up or down an 
incline, ascertain the resistance on a level road having the same 
surface as the incline, to which add, if the vehicle ascends, or sub¬ 
tract, if it descends, the force requisite to sustain it on the incline; 
the sum or difference, as the case may be, will express the resistance. 

531. Tractive Power and Gradients.—The necessity for easy 
grades is dependent upon the power of the horse to overcome the 
resistance to motion composed of the four forces, friction, collision, 
gravity, and the resistance of the air. 

All estimates on the tractive power of horses must to a certain 
extent be vague, owing to the different strengths and speeds of 
animals of the same kind, as well as to the extent of their training 
to any particular kind of work.. Authorities on the subject differ 
widely, and sometimes express themselves in a loose manner that 
throws doubt on their meaning. 

532. The draught or pull which a good average horse, weighing 
1200 pounds, can exert on a level, smooth road at a speed of 2% 
miles per hour is 100 pounds, equivalent to 22,000 foot-pounds per 
minute, or 13,200,000 foot-pounds per day of 10 hours. 

533. The tractive power diminishes as the speed increases and 
perhaps, within certain limits, say from f to 4 miles per hour, nearly 







RESISTANCE TO TRACTION. 


301 


in inverse proportion to it. Tims the average tractive force of a 
horse, on a level, and actually pulling for 10 hours, may be assumed 
approximately as follows: 


TABLE LIII. 

Tractive Power of Horses at Different Velocities. 


Miles per hour. 

Tractive Force. 
Pounds. 

Miles per hour. 

Tractive Force. 
Pounds. 

f. 

333.33 

24. 

Ill 11 

1 . 

250 

24. 

100 

14. 

200 


90 91 

14. 

166.66 

3. 

83 33 

If. 

142.86 

34. 

71.43 

2‘. 

125 

4. 

62.50 






534. The work done by a horse is greatest when the velocity 
with which he moves is -J of the greatest velocity with which he can 
move when unloaded; and the force thus exerted is 0.45 of the 
utmost force that he can exert at a dead pull. 


TABLE LIV. 

Duration of a Horse’s Daily Labor and Maximum Velocity Unloaded. 


Duration of Labor. 
Hours. 

Maximum Velocity. 
Miles per hour. 

Duration of Labor. 
Hours. 

Maximum Velocity. 
Miles per hour. 

1 .. 

14.7 

6. 

6.0 

2. 

10.4 

7. 

5.5 

3. 

8.5 

8. 

5.2 

4 .. . 

7.3 

9. .. 

4.9 

5. 

6.6 

10.. 

4.6 






535. The tractive power of a horse may be increased in about 
the same proportion as the time is diminished, so that when working 
from 5 to 10 hours, on a level, it will be about as shown in the fol¬ 
lowing table: 

TABLE LV. 


Hours per day. 

Traction (pounds). 

Hours per day. 

Traction (pounds). 

10 . 

100 

7. 

146# 

9. 

1114 

6 . 

166f 

200 

8 . 

125 

5. 




































































302 


HIGHWAY CONSTRUCTION. 


Table LYI is useful as showing the maximum amount of labor 
a horse of average strength is capable of performing at different 
rates of speed. 

TABLE LYI. 


Speed in 
Miles per hour. 

Duration of the 
Day’s Work. 

Resistance to 
Traction. 

Useful Effect of On 
day in tons d 

On Level Iron Rails. 
Tons. 

e Horse working 1 
rawn 1 mile. 

On Level Maca¬ 
dam. Tons. 

2^ 

Hi 

83i 

115 

14 

3 

8 

83* 

92 

12 

3£ 

K 9 
°i5r 

83* 

82 

10 

4 

4i 

83i 

72 

9 

5 

O 9 

83b 

57 

7.2 

6 

2 

83 i 

48 

6.0 

7 

n 

83 i 

41 

5.1 

8 

H 

83 b 

36 

4.5 

9 

TO - 

83 i 

32 

4.0 

10 

f 

83 i 

28.8 

3.6 


536. Loss of Tractive Power on Inclines. —In ascending inclines 
a horse’s power diminishes rapidly; a large portion of his strength 
is expended in overcoming the resistance of gravity due to his own 
weight and that of the load. Table LYIII shows that as the steep¬ 
ness of the grade increases the efficiency of both the horse and the 
road-surface diminishes; that the more the horse’s energy is ex¬ 
pended in overcoming gravity the less remains to overcome the 
surface-resistance. 

Table LYII shows the gross load which an average horse. 


TABLE LYII. 


Description of Surface. 

Level. 

5 per cent. 
Grade. 

10 per cent. 
Grade. 

Asphalt. 

Pounds. 

13,216 

6,700 

Pounds. 

Pounds. 

Broken stone (best condition).. 

1,840 

1,060 

“ (slightly muddy). 

4,700 

1,500 

1,000 

“ “ (ruts and mud). 

3,000 

1,390 

890 

“ (very bad condition). 

1,840 

1,040 

740 

Earth (best condition). 

3,600 

1,500 

930 

“ (average condition). 

1,400 

900 

660 

“ (moist but not muddy). 

1,100 

780 

600 

Stone-block pavement (dry and clean). 

8,300 

1,920 

1,090 

“ “ “ (muddy). 

6,250 

1,800 

1,040 

Sand (wet).. 

1,500 

675 

390 

*' (dry). 

1,087 

445 

217 










































RESISTANCE TO TRACTION. 


303 


weighing 1200 pounds, can draw on different kinds of road-surfaces, 
on a level and on grades rising five and ten feet per one hundred 
feet. 

537. The decrease in the load which a horse can draw upon an 
incline is not due alone to gravity; it varies with the amount of 
foothold afforded by the road-surface. The smoother the surface the 
less the foothold, and consequently the load. Table LVIII shows 
the decrease in the loads caused by various road-coverings on grades 
from 1 to 20 per cent. 

TABLE LVIII. 

Effect of Grades upon the Loads a Horse can draw on Different 

Pavements. 


Grade. 

Earth. 

Broken Stone. 

Stone Blocks. 

Asphalt. 

Level. 

1.00 

1.00 

1.00 

1.00 

1 -100. 

.80 

.66 

.72 

.41 

2 • 100... 

.06 

.50 

.55 

.25 

3 • 100. 

.55 

.40 

.44 

.18 

4-100 . 

.47 

.33 

.36 

.13 

5-100. 

.41 

.29 

.30 

.10 

10 • 100.. 

.26 

.16 

.14 

.04 

15 : 100. 

.10 

.05 

.07 

20 • 100. 

.04 

.03 






538. The loss of tractive power on inclines is greater than any 
investigation will show; for, besides the increase of draught caused 
by gravity, the power of the horse is much diminished by fatigue 
upon a long ascent, and even in greater ratio than man, owing to its 
anatomical formation and great weight. Though a horse on a level 
is as strong as five men, on a grade of 15 per cent, it is less strong 
than three; for three men carrying each 100 pounds will ascend 
such a grade faster and with less fatigue than a horse with 300 
pounds. 

539. A horse can exert for a short time twice the average trac¬ 
tive pull which he can exert continuously throughout a day's work; 
hence, so long as the resistance on the incline is not more than 
double the resistance on the level, the horse will be able to take up 
the full load which he is capable of drawing. 

540. Steep grades are thus seen to be objectionable, and partic¬ 
ularly so when a single one occurs on an otherwise comparatively 
level road, in which case the load carried over the less inclined por¬ 
tions must be reduced to what can be hauled up the steeper portion. 



























304 


HIGHWAY CONSTRUCTION. 


541. The bad effects of steep grades are especially felt in winter, 
when ice covers the roads, for the slippery condition of the surface 
causes danger in descending, as well as increased labor in ascending; 
the water of rains also runs down the road and gulleys it out, 
destroying its surface, thus causing a constant expense for repairs. 
The inclined portions are subjected to greater wear from the feet 
of horses ascending, thus requiring thicker covering than the more 
level portions, and hence increasing the cost of construction. 

542. It will rarely be possible, except in a flat or comparatively 
level country, to combine easy grades with the shortest and most 
direct route. These two requirements will often conflict; in such a 
case increase the length. The proportion of this increase will 
depend upon the friction of the covering adopted. But no general 
rule can be given to meet all cases as respects the length which may 
thus be added, for the comparative time occupied in making the 
journey forms an important element in any case which arises for 
settlement. Disregarding time, the horizontal length of a road ma} 7- 
be increased, to avoid a 5 per cent grade, seventy times the height. 

Table LIX shows with sufficient exactness for most practical 

TABLE LIX. 


Rate 
of Grade. 
Feet per 
100 feet. 

1 

j 

Pressure on 
the Plane in 
lbs. per ton. 

Tendency 
| down the 
Plane in lbs. 
per ton. 

Power in lbs. 
required to 
haul one ton 
up the Plane. 

Equivalent 
Length of 
Level Road. 
Miles. 

Maximum 
Load in lbs. 
which a Horse 
can haul. 

0.0 

2240 

00 

45.00 

1.000 

6270 

0.25 

( i 

5.60 

50.60 

1.121 

5376 

0.50 

i < 

11.20 

56.20 

1.242 

4973 

0.75 

( c 

16.80 

61.80 

1.373 

4490 

1 

* << 

22.40 

67.40 

1.500 

4145 

1.25 

< < 

28.00 

73.00 

1.622 

3830 

1.50 

< < 

33.60 

78.60 

1.746 

3584 

1.75 

a 

39.20 

84.20 

1.871 

3290 

2 

n 

45.00 

90.00 

2.000 

3114 

2.25 

t < 

50.40 

95.40 

2.120 

2935 

2.50 

c < 

56.00 

101.00 

2.244 

2725 

2.75 

< < 

61.33 

106.33 

2.363 

2620 

3 

2239 

67.20 

112.20 

2.484 

2486 

4 

2238 

89.20 

134.20 

2 982 

2083 

5 

2237 

112.00 

157.00 

3.444 

1800 

6 

2233 

134.40 

179.40 

3.986 

1568 

7 

2232 

156.80 

201.80 

4.844 

1367 

8 

( t 

179.20 

224.20 

4.982 

1235 

9 

2231 

201.60 

246.60 

5.480 

1125 

10 

2229 

224.00 

269.00 

5.977 

1030 


-- — --------- - - - -- 

* Near enough for practice, actually 2239.888. 

Pressure on the plane — weight X nat cos of angle of plane. 





























RESISTANCE TO TRACTION. 


305 


purposes the force required to draw loaded vehicles over inclined 
roads. The first column expresses the rate of inclination; the second, 
the pressure on the plane in pounds per ton; the third, the tendency 
down the plane (or force required to overcome the elfect of gravity) 
in pounds per ton; the fourth, the force required to haul one ton up 
the incline; the fifth, the length of level road which would be 
equivalent to a mile in length of the inclined road—that is, the 
length which would require the same motive power to be expended 
in drawing the load over it as would be necessary to draw it over a 
mile of the inclined road; the sixth, the maximum load which an 
average horse weighing 1200 pounds can draw over such inclines, 
the friction of the surface being taken at ^ of the load drawn. 

543. Character of Vehicles. —The character of the vehicles used 
upon'a roadway has a great influence upon its endurance to the 
beat of the wheels. The great defect of our vehicles is that for a 
given load the tires of the wheels are too narrow. It has been 
proved by repeated and careful experiments that wheels with tires 
two and a half inches wide cause double the wear of wheels which 
have tires four and a half inches wide. It is true that on ill-con¬ 
ditioned and muddy roads a narrow wheel-tread is advantageous, 
for the reason that the thick mud has a less extended hold when it 
wraps around the felloes and spokes; but with this arrangement 
the interests of the roadway are sacrificed to the convenience of the 
individual w r ho drives upon it. 

544. The width of the surface covered by these narrow tires is 
not sufficient to bear the heavy load imposed upon it, and the knife¬ 
like tire cuts into it, forming and deepening ruts. The proper 
width of tire, or proper load upon any vehicle for a given width of 
tire, is a question that deserves more attention than is usually 
accorded to it. 

545. The best width of tire measured when new is shown in 
Table LX. 

These widths are best for easy traction and the maximum wear 
of the road-surface. To make the tires wider does not diminish the 
force required to move the load, and unnecessarily increases the 
dead weight of the vehicles. For carriages, coupes, and vehicles 
for light passenger use the tires need not exceed 2^ inches and 

should never be less than 2 inches. 

The width of tires should be established by law. 




30G 


HIGHWAY CONSTRUCTION. 


TABLE LX. 


Hoad on each 
Wheel. 

Description of Vehicles. 

Two Wheels 
without Springs. 
Inches. 

Two Wheels 
with Springs. 
Inches. 

Four Wheels 
without Springs. 
Inches. 

Four Wheels 
with Springs. 
Inches. 

i ton 

6 

3 

5 

3 

4 “ 

6 

3 

5 

3 

1 “ 



5 

34 

14 “ 



5 

4 

2 “ 



6 

44 


546. The freight and market wagons of France have tires from 
3 to 10 inches in width, usually from 4 to 6 inches. The four- 
wheeled freight-wagons have tires rarely less than 6 inches and the 
rear axle is about 14 inches longer than the fore, so that the rear 
wheels run on a line about an inch outside of the line of the fore¬ 
wheels. The varied gauge is also usually observed with cabs, hacks, 
.and other four-wheeled vehicles. 

547. In Bavaria the width of the wheel-tires is laid down by law 


as follows: 

2-wheeled carts with 2 horses....4.133 inches 

“ “ “ 4 “ . 6.180 “ 

4-wheeled carts with 2 “ . 2.596 “ 

“ “ “ 3 or 4 horses. 4.133 “ 

“ “ “ 5 to 8 “ . 6.180 


Carts with more than four and wagons with more than-eight 
horses are not allowed to use the road except under special permit 
from the authorities. 

548. In Austria the width of tires for wagons carrying 2^ tons 
tons is 4.33 inches, and for wagons carrying 4^ tons 6.30 inches. 

548a. In June, 1892, the Studebaker Bros. Mfg. Co. of South 
Bend, Ind., made a series of tests to determine the relative merits of 
wide and narrow tires with regard to the resistance they offered to 
traction upon different road-surfaces. The wagon employed was a 
regular 3|-inch thimble-skein wagon having in one set of tests 
wheels 3 feet 8 inches and 4 feet 6 inches in diameter, and in 
another set 3 feet 6 inches and 3 feet 10 inches. A Fairbanks 
dvnamometer was attached to the double-tree, and the team exerted 
their pull through the instrument to move the load. 

The tests showed that the width of tire has very little effect upon 
























RESISTANCE TO TRACTION. 


307 


the power required to move loads upon hard surfaces, such as stone 
blocks, hard sand, or gravel, the power required to move a load 
of one ton (2240 pounds) being on 

Stone blocks with 1^-in. tire 168 pounds; with 4-in. tire 180pounds. 

Hard sand “ “ “ “ 383 “ “ “ “ “360 

Hard gravel “ “ “ “ 344 “ “ “ “ “ 311 

Upon soft ground, such as mud and grass sods, into which the 

narrow tires would cut, the wide tires have a slight advantage, the 
power required to move one ton (2240 pounds) beiug on 
Soft mud with 1-J-in. tire 476 pounds; with 4-in. tire 412 pounds. 
Sod “ “ “ “ 610 “ “ 3 “ “ 537 

The power required to keep the load in motion after being 
started was found to range from 25 to 50 per cent less than 
that required to start it. It was also found that less power 
was required to start the load when wheels of large diameter were 
employed, and that the diameter of the wheel had no apparent ef¬ 
fect on the power required to keep the load in motion. 

549. Size of Wheels. —The wheels of a vehicle serve a twofold 
purpose. In the first place, they diminish the friction on the 
ground by transferring it from the circumference to the nave and 
axle; and in the second place, they serve to raise the vehicle more 
easily over obstacles met with on roads. 

550. The friction is diminished in the proportion of the circum¬ 
ference of the axle to that of the wheel; and hence the larger the 
wheel and the smaller the axle the less is the friction. 

The mechanical advantage of the wheel in surmounting an 
obstacle may be computed from the principle of the lever. 

Let the wheel, Fig. 41, touch the horizontal line of traction in the 
point A and meet a protuberance BD. Suppose the line of draught 
CP to be parallel to AB. Join CD and draw the perpendiculars 
DE and DF. We may suppose the power to be applied at E and 
the weight at F, and the action is then the same as the bent lever 
EDF turning round the fulcrum at D. Hence P : W :: FD : DE, 
but FD : DE :: tan FCD : 1, and tan FCD — tan 2 [DAB)', 
therefore P = W tan 2 (DAB). Now it is obvious that the 
angle DAB increases as the radius of the circle diminishes; and 
therefore, the weight W being constant, the power required to 
overcome an obstacle of a given height is diminished when the 



308 


HIGHWAY CONSTRUCTION. 



Fig. 41. 

diameter is increased. Large wheels are therefore the best adapted 
for surmounting inequalities of the road. 

551. There are, however, circumstances which provide limits to 
the height of the wheels of vehicles. If the radius A C exceeds the 
height of that part of the horse to which the traces are attached, 
the line of traction CP will be inclined to the horse, and part of 
the power will be exerted in pressing the wheel against the ground. 
The best average size of wheels is considered to be about 6 feet in 

diameter. 

* 

552. Wheels of large diameter do less damage to a road than 
small ones, and cause less draught for the horses. 

553. With the same load a two-wheeled cart does far more 
damage than one with four wheels, and this because of their sud¬ 
den and irregular twisting motion in the trackway. 

554. Springs materially decrease the resistance and act pre- 
servingly on both road and vehicle. 







CHAPTER XI. 


LOCATION OF COUNTRY ROADS. 

555. The considerations governing the location of country roads 
.are dependent upon the commercial condition of the country to be 
traversed. In old and long-inhabited sections the controlling ele¬ 
ment will be the character of the traffic to be accommodated. In 
such a section the route is generally predetermined, and therefore 
there is less liberty of a choice and selection than in a new and 
sparsely settled district, where the object is to establish the easiest, 
shortest, and most economical line of intercommunication accord¬ 
ing to the physical character of the ground. 

556. Whichever of these two cases may have to be dealt with, 
the same principle governs the engineer, namely, to so lay out the 
road as to effect the conveyance of the traffic with the least ex¬ 
penditure of motive power consistent with economy of construction 
and maintenance. 

557. Economy of motive power is promoted by easy grades, by 
the avoidance of all unnecessary ascents and descents, and by a 
direct line; but directness must be sacrificed to secure easy grades 
and to avoid expensive construction. 

558. Reconnoissance. —The selection of the best route demands 
much care and consideration on the part of the engineer. To 
obtain the requisite data upon which to form his judgment he 
must make a personal reconnoissance of the district. This requires 
that the proposed route be either ridden or walked over and a 
careful examination made of the principal physical contours and 
natural features of the district. The amount of care demanded 
and the difficulties attending the operations will altogether depend 
upon the character of the country. 

559. The immediate object of the reconnoissance is to select 
one or more trial lines, from which the final route may be ultimate¬ 
ly determined. 


309 


310 


HIGHWAY CONSTRUCTION. 


When there are no maps of the section traversed, or when those 
which can be procured are indefinite or inaccurate, the work of 
reconnoitring will be much increased. 

560. In making a reconnoissance there are several points which, 
if carefully attended to, will very considerably lessen the labor and 
time otherwise required. Lines which would run along the imme¬ 
diate bank of a large stream must of necessity intersect all the 
tributaries confluent on that bank, thereby demanding a corre¬ 
sponding number of bridges. Those, again, which are situated along 
the slopes of hills are more liable in rainy weather to suffer from 
washing away of the earthwork and sliding of the embankments; 
the others which are placed in valleys or elevated plateaux, when 
the line crosses the ridges dividing the principal water-courses will 
have steep ascents and descents. 

561. In making an examination of a tract of country, the first 
point to attract notice is the unevenness or undulations of its sur¬ 
face, which appears to be entirely without system, order, or arrange¬ 
ment; but upon closer examination it will be perceived that one 
general principle of configuration obtains even in the most irregular 
countries. The country is intersected in various directions by main 
water-courses or rivers, which increase in size as they approach the 
point of their discharge. Towards these main rivers lesser rivers ap¬ 
proach on both sides, running right and left through the country, 
and into these, again, enter still smaller streams and brooks. The 
streams thus divide the hills into branches or spurs having approx¬ 
imately the same direction as themselves, and the ground falls in 
every direction from the main chain of hills towards the water¬ 
courses, forming ridges more or less elevated. 

562. The main ridge is cut down at the heads of the streams 
into depressions called gaps or passes; the more elevated points are 
called peaks. The water which has fallen upon these peaks is the 
origin of the streams which have hollowed out the valleys. Further¬ 
more, the ground falls in every direction towards the natural water¬ 
courses, forming ridges more or less elevated running between them 
and separating from each other the districts drained by the streams. 

563. The natural water-courses mark not only the lowest lines, 
but the lines of the greatest longitudinal slope in the valleys 
through which they flow. 

564. The direction and position of the principal streams give 




LOCATION OF COUNTRY ROADS. 


311 


also the direction and approximate position of the high ground or 
ridges which lie between them. 

565. The position of the tributaries to the larger stream gener¬ 
al^ indicates the points of greatest depression in the summits of 
the ridges, and therefore the points at which lateral communication 
across the high ground separating contiguous valleys can be most 
readily made. 

566. The instruments employed in reconnoitring, are:—The 
compass, for ascertaining the direction; the aneroid barometer, to 
fix the approximate elevation of summits, etc.; and the hand-level, 
to ascertain the elevation of neighboring points. If a vehicle can be 
used, an odometer may be added, but distances can usually be 
guessed or ascertained by time estimates or otherwise, closely 
enough for preliminary purposes. More outfit than the above (the 
use of which is supposed to be understood), with the best maps ob¬ 
tainable and a succession of travelling companions who possess a 
local knowledge of the country, will not be particularly useful. 

567. The reconnoissance being completed, instrumental surveys 
of the routes deemed most advantageous should be made. When 
the several lines are plotted to the same scale, a good map can be 
prepared from which the exact location of the road can be deter¬ 
mined. 

568. In making the preliminary surveys the topographical 
features should be noted for a convenient distance to the right 
and left of the line, and all prominent points located by compass- 
bearings. The following data should be also obtained: the impor¬ 
tance, magnitude, and direction of all streams and roads crossed; 
the character of the material to be excavated or available for em¬ 
bankments, the position of quarries and gravel-pits, and the modes 
of access thereto; and all other information that may effect a selec¬ 
tion. 

569. Topography.—There are various methods of delineating 
upon paper the irregularities of the surface of the ground. The 
method of most utility to the engineer is that by means of “contour 
lines.” These are fine lines traced through the points of equal level 
over the surface surveyed, and denote that the level of the ground 
throughout the whole of their course is identical; that is to say, that 
every part of the ground over which the line passes is at a certain 





312 


HIGHWAY CONSTRUCTION. 


height above a known fixed point termed the datum, this height 
being indicated by the figures written against the line. 

The intervals between the lines vertically is equal and may be 
1, 3, 5, 10, or more feet apart; 5 feet will be found the most useful. 

The rate of inclination of the ground may be estimated by the 
relative proximity or distance apart of the lines. Where the ground 
is comparatively level they are far apart; where the surface is very 
hilly they lie close together. 

These lines by their greater or less distance apart have the effect 
of shading, and make apparent to the eye the undulations and 
irregularities in the surface of the 'country. 

Fig. 42 shows an imaginary tract of country the physical features 
of which are shown by contour lines. 

570. Map .—The map should show the lengths and direction of 
the different portions of the line, the topography, rivers, water¬ 
courses, roads, railroads, and other matters of interest, such as town 
and county lines, dividing lines between jiroperty, timbered and 
cultivated lands, etc. 

Any convenient scale may be adopted; 400 feet to an inch will 
be found the most useful. 

Fig. 43 shows a map of this kind. 

571. Memoir. —The descriptive memoir should give with minute¬ 
ness all information such as the nature of the soil, character of the 
several excavations whether earth or rock, and such particular fea¬ 
tures as cannot clearly be shown on the map or profile. 

Special information should be given concerning the rivers 
crossed, as to their width, depth at highest known flood, velocity of 
current, character of banks and bottom, and the angle of skew 
which the course makes with the line of the road. 

572. Levels.—Levels should be taken along the course of each 
line, usually at every 100 feet, or at closer intervals depending upon 
the nature of the country. 

In taking the levels, the heights of all existing roads, railroads, 
rivers, or canals should be noted. “ Bench-marks ” should be es¬ 
tablished at least every half-mile that is, marks made on any fixed 
object such as a gate-post, side of a house, or, in the absence of these, 
a cut made on a large tree. The height and exact description of each 
bench-mark should be recorded in the level book. 

573. Cross-levels. —Wherever considered necessarv levels at 





LOCATION OF COUNTRY ROADS. 


313 





























































314 


HIGHWAY CONSTRUCTION. 


















LOCATION OF COUNTRY ROADS. 


315 



right angles to the centre line should 
be taken. These will be found useful 
in showing what effect a deviation to 
the right or left of the surveyed line 
would have. Cross-levels should be 
taken at the intersection of all roads 
and railroads to show to what extent, 
if any, these levels will have to be 
altered to suit the levels of the pro¬ 
posed road. 

574. Profile. — A profile is a longi¬ 
tudinal section of the route, made from 
the levels. Its horizontal scale should 
be the same as that of the map; the 
vertical scale should be such as will 
show with distinctness the inequalities 
of the ground. 

Fig. 44 shows the manner in which 
a profile is drawn and the nature of 
the information to be given upon it. 

575. Bridge Sites. —Thequestion of 
choosing the site of bridges is an im¬ 
portant one. If the selection is not 
restricted to a particular point, the 
river should be examined for a con¬ 
siderable distance above and below what 
w 7 ould be the most convenient point for 
crossing; and if a better site is found, 
the line of the road must be made sub¬ 
ordinate to it. If several practicable 
crossings exist, they must be carefully 
compared in order to select the one 
most advantageous. The following are 
controlling conditions: (1) Good char¬ 
acter of the river-bed, affording a firm 
foundation. If rock is present near 
the surface of the river-bed, the foun¬ 
dation will be easy of execution and 
stability and economy will be insured. 
















31G 


HIGHWAY CONSTRUCTION. 


(2) Stability of the river-banks, thus securing a permanent con¬ 
centration of the waters in the same bed. (3) The axis of the 
bridge should be at right angles to the direction of the current. 
(4) Bends in the river are not suitable localities and should be 
avoided if possible. A straight reach above the bridge should be 
secured if possible. 

576. Principles to be observed in making the Final Selection. 

In making the final selection the following principles should be 
observed as far as practicable. 

(( a ) To follow that route which affords the easiest grades. The 
easiest grade for a given road will depend upon the kind of cover¬ 
ing adopted for its surface 

(b) To connect the places by the shortest and most direct route 
commensurate with easy grades. 

(c) To avoid all unnecessary ascents and descents. When a road 
is encumbered with useless ascents, the wasteful expenditure of 
power is considerable. 

(d) To give the centre line such a position, with reference to 
the natural surface of the ground, that the cost of construction 
shall be reduced to the smallest possible amount. 

(e) To cross all obstacles (where structures are necessary) as 
nearly as possible at right angles. The cost of skew structures in¬ 
creases nearly as the square of the secant of the obliquity. 

(/) To cross ridges through the lowest pass which occurs. 

(g) To cross either under or over railroads; for grade crossings 
mean danger to every user of the highway. Guards and gates fre¬ 
quently fail to afford protection, and the daily press is filled with 
accounts of accidents more or less serious; and while statistics fail 
to give total casualties, the aggregate must be great. 

577. Examples of Cases to be Treated.—In laying out the line 
of a road, there are three cases which may have to be treated, and 
each of these is exemplified in the contour map Fig. 42, page 278. 
First, the two places to be connected, as the towns A and B on the 
plan, may be both situated in the same valley, and upon the same 
side of it; that is, they are not separated from each other by the 
main stream which drains the valley. This is the simplest case. 
Secondly, although both in the same valley, the two places may be on 
opposite sides of the valley, as at A and C, being separated by the 
main river. Thirdly, they may be situated in different valleys, sep- 



LOCATION OF COUNTRY ROADS. 


317 

arated by an intervening ridge of ground more or less elevated, as at 
A and D. In laying out an extensive line of road, it frequently 
happens that all these cases have to be dealt with; frequently, per¬ 
haps, during its course. 

The most perfect road is that of which the course is perfectly 
straight and the surface practically level; and, all other things 
being the same, that is the best road which answers nearest to this 
description. 

Now in the first case, that of the two towns situated on the same 
side of the main valley, there are two methods which may be pur¬ 
sued in forming a communication between them. A road follow¬ 
ing the direct line between them, shown by the thick dotted line 
AB, may be made, or a line may be adopted which will gradually 
and equally incline from one town to the other, supposing them to 
be at different levels, or which should keep, if they are on the same 
level, at that level throughout its entire course, following all the 
sinuosities and curves w'hich the irregular formation of the country 
may render necessary for the fulfilment of these conditions. 
According to the first method, a level or uniformly inclined road 
might be made from one to the other; this line would cross all the 
valleys and streams which run down to the main river, thus neces¬ 
sitating deep cuttings, heavy embankments, and numerous bridges; 
or these expensive works might be avoided by following the sinu¬ 
osities of the valley. When the sides of the main valley are pierced 
by numerous ravines with projecting spurs and ridges intervening, 
instead of following the sinuosities, it will be found better to make 
a nearly straight line cutting through the projecting points in such 
a way that the material excavated should be just sufficient to fill 
the hollows. * 

Now, of all these, the best is the straight and uniformly in¬ 
clined, or the level road, although at the same time it is the most 
expensive. If the importance of the traffic passing between the 
places is not sufficient to warrant so great an outlay, it will become 
a matter of consideration whether the course of the road should be 
kept straight, its surface being made to undulate with the natural 
face of the country; or whether, a level or equally inclined line 
being adopted, the course of the road should be made to deviate 
from the direct line and follow the winding course which such a 
condition is supposed to necessitate. 






318 


HIGHWAY CONSTRUCTION. 


In the second case, that of two places situated on opposite sides 
of the same valley, there is, in like manner, the choice of a per¬ 
fectly straight line to connect them, which would probably require 
a high embankment if the road was kept level, or steep inclines if 
it followed the surface of the country; or by winding the road, it 
may be carried across the valley at a higher point, where, if the 
level road be taken, the embankment would not be so high, or, if 
kept on the surface, the inclination would be reduced. 

In the third case, there is, in like manner, the alternative of 
carrying the road across the intervening ridge in a perfectly straight 
line, or of deviating it to the right 'and left, and crossing the ridge at 
a point where the elevation is less. 

The proper determination of the question which of these 
courses is the best under certain circumstances involves a con¬ 
sideration of the comparative advantages and disadvantages of 
inclines and curves. What additional increase in the length of a 
road would be equivalent to a given inclined plane upon it; or, 
conversely, what inclination might be given to a road as an 
equivalent to a given decrease in its length ? To satisfy this ques¬ 
tion it is requisite to know the comparative force required to draw 
different vehicles with given loads upon level and upon variously 
inclined roads—a subject which is treated in Chapter X. 

The route which will give the most general satisfaction con¬ 
sists in following the valleys as much as possible and rising after¬ 
ward by gentle grades. This course traverses the cultivated lands, 
regions studded with farm-houses and factories. The value of such 
a line is much more considerable than that of a route by the 
ridges. The water-courses which flow down to the main valley 
are, it is true, crossed where they are the largest, and require works 
of large dimensions, but also they are fewer in number. 

578. Intermediate Towns.—Suppose that it is desired to form a 
road between two distant towns, A and B, Fig. 45, and let us 
for the present neglect altogether the consideration of the physical 
features of the intervening country, assuming that it is equally 
favorable whatever line we select. Xow at first sight, it would ap¬ 
pear that under such circumstances a perfectly straight line drawn 
from one town to the other would be the best that could be chosen. 
On more careful examination, however, of the locality, we may find 
that there is a third town, C, situated somewhat on one side of the 




LOCATION OF COUNTRY ROADS. 


319 


straight line which we have drawn from A to B; and although our 
primary object is to connect only the two latter, that it would 
nevertheless be of considerable service if the whole of the three 


C 


\ 


y 


y 


y 


y 


\ 


K 


0 


B 


Fig. 45. 

towns were put into mutual connection with each other. Now this 
may be effected in three different ways, any one of which might, 
under the circumstances, be the best. In the first place, we might, 
as originally suggested, form a straight road from A to B, and in a 
similar manner two other straight roads from A to C, and from B 
to 0, and this would be the most perfect way of effecting the 
object in view, the distance between any two of the towns being 
reduced to the least possible. It would, however, be attended with 
considerable expense, and it would be requisite to construct a much 
greater length of road than according to the second plan, which 
would be to form, as before, a straight road from A to B, and from 
C to construct a road which should join the former at a point D, 
so as to be perpendicular to it. The traffic between A or B and C 
would proceed to the point D and then turn off to 0. With this 
arrangement, while the length of the roads would be very materi¬ 
ally decreased, only a slight increase would be occasioned in the 
distance between C and the other two towns. The third method 
would be to form only the roads AC and CB, in which case the dis¬ 
tance between A and B would be somewhat increased, while that 
between AC or B and C would be diminished, and the total length 
of road to be constructed would also be lessened. 

A.s a general rule it may be taken that the last of these methods 
is the best and most convenient for the public, that is to say, that if 
the physical character of the country does not determine the 
course of the road, it will generally be found best not to adopt a 





320 


HIGHWAY CONSTRUCTION'. 


perfectly straight line, but to vary the line so as to pass through 
all the principal towns near its general course. 

579. Mountain Roads. —The location of roads in mountainous 
countries presents greater difficulties than in an ordinary undulating 
country; the same latitude in adopting undulating grades and choice 
of position is not permissible, for the maximum gradient must be kept 
before the eye perpetually. A mountain road has to be constructed 
on the maximum grade or at grades closely approximating it, and 
but one fixed point can be obtained before commencing the survey, 
and that is the lowest pass in the mountain range; from this point 
the survey must be commenced. The reason for this is that the 
lower slopes of the mountains are flatter than those at their 
summit; they cover a larger area and merge into the valley in 
diverse undulations. So that a road at a foot of a mountain may be 
carried at will in the desired direction by more than one route, 
while at the top of a mountain range any deviation from the 
lowest pass involves increased length of line. The engineer having 
less command of the ground, owing to the reduced area he has to 
deal with and the greater abruptness of the slopes, is liable to be 
frustrated in his attempt to get his line carried in the direction he 
wishes it to follow. 

580. It is a common practice to run a mountain survey up-hill, 
but such practice should be avoided. Wherever an acute-angled 
zigzag is met with on a mountain road near the summit, the infer¬ 
ence to be drawn is that the line being carried up-hill on reaching 
the summit was too low and the zigzag was necessary to reach the 
desired pass. The only remedy in such a case is by a resurvey 
beginning at the summit and running down-hill. This method 
requires a reversal of the usual one. The grade line is first staked 
out and its horizontal location surveyed afterwards. The most 
appropriate instrument for this work is a transit with a vertical 
circle on which the telescope may be set to the angle of the maxi¬ 
mum grade. 

581. Loss of Height.— Loss of height is to be carefully avoided 
in a mountain road. By loss of height is meant an intermediate 
rise in a descending grade. If a descending grade is interrupted 
by the introduction of an unnecessary ascent, the length of the 
road will be increased over that due to the continuous grade by the 
length of the portion of the road intervening between the summit 



LOCATION OF COUNTRY ROADS. 


321 


of the rise and the point in the road in a level with that rise—a 
length which is double that due on the gradient to the height of 
the rise. For example, if a road descending a mountain rises at 
some intermediate point to cross over a ridge or spur, and the 
height ascended amounts to 110 feet before the descent is con¬ 
tinued, such a road would be just one mile longer than if the 
descent had been uninterrupted; for 110 feet is the rise due to a. 
half-mile length at 1:24. 

582. Water on Mountain Roads.—Water is needed by the work¬ 
men and during the construction of the road; it is also very neces¬ 
sary for the traffic, especially during hot weather; and if the road 
exceeds 5 miles in length provision should be made to have it 
either close to or within easy reach of the road. With a little in¬ 
genuity the water from springs above the road, if such exist, can be 
led down to drinking-fountains for men, and to troughs for 
animals. 

In a tropical country it would be a matter for serious considera¬ 
tion if the best line for a mountain road 10 miles in length or up¬ 
wards, but without water, should not be abandoned in favor of a 
worse line with a water-supply available. 

583. Halting-places.—On long lines of mountain roads halting- 
places should be provided at convenient intervals. 

584. Alignment.—No hard and fast rule can be laid down for 
the alignment of a road; it will depend both upon the character 
of the traffic on it and upon the “ lay of the land.” To promote 
economy of transportation it should be straight; but if straight¬ 
ness is obtained at the expense of easy grades that might have 
been obtained by deflections and increase of length, it will' prove 
very expensive to the community that uses it. 

585. Where curves are necessary, employ the greatest radius pos¬ 
sible and never less than fifty feet. They may be circular or 
parabolic. The parabolic will be found exceedingly useful for join¬ 
ing tangents of unequal length, and for following contour.lines; 
its curvature being least at its beginning and ending, makes the 
deviations from a straight line less strongly marked than by a 
circular arc (see Figs. 46 to 49). 

586. When a curve occurs on an ascent, the grade at that place 
must be diminished in order to compensate for the additional 
resistance of the curve. 





322 


HIGIIWAY CONST K UCTLON. 


TYPES OF CURVES. 



Fig. 49. 

DOUBLE-REVERSE CURVE 









LOCATION OF COUNTRY ROADS. 


323 


587. The width of the wheelway on curves must be increased. 
This increase should be one quarter of the width for central angles 
between 90 and 120 degrees, and one half for angles between 60 
and 90 degrees. 

588. Excessive crookedness of alignment is to be avoided, for 
any unnecessary length causes a constant threefold waste: first, 
of the interest of the capital expended in making that unnecessary 
portion; secondly, of the ever-recurring expense of repairing it; 
and thirdly, of the time and labor employed in travelling over it. 

589. The curving road around a hill may be often no longer 
than the straight one over it, for the latter is straight only with 
reference to the horizontal plane, while it is curved as to the verti¬ 
cal plane; the former is curved as to the horizonal plane, but 
straight as to the vertical plane. Both lines curve, and we call the 
one passing over the hill straight only because its vertical curva¬ 
ture is less apparent to our eyes. 

590. The difference in length between a straight road and one 
which is slightly curved is very small. If a road between two 
places ten miles apart were made to curve so that the eye could 
nowhere see farther than one quarter of a mile of it at once, its 
length would exceed that of a straight road between the same 
points by only about four hundred and fifty feet. 

591. Zigzags.—The method of surmounting a height by a 
series of zigzags, or by a series of reaches with practicable curves 
at the turns, is objectionable. 

(1) An acute-angled zigzag obliges the traffic to reverse its 
direction without affording it convenient room for the purpose. 
The consequence is that with slow traffic a single train of vehicles 
is brought to a stand, while if two trains of vehicles travelling in 
opposite directions meet at a zigzag a block ensues. 

(2) With zigzags little progress is made towards the ultimate 
destination of the road; height is surmounted, but horizontal dis¬ 
tance is increased for which there is no necessity or compensation. 

(3) Zigzags are dangerous. In case of a runaway down-hill the 
zigzag must prove fatal. 

(4) If the drainage cannot be carried clear of the road at the 
end of each reach, it must be carried under the road in one reach 
only to appear again at the next, when a second bridge, culvert, or 
drain will be required, and so on at the other reaches. If the 




324 


HIGHWAY COXSTIiUCTIOX. 


drainage can be carried clear at the termination of each reach, the 
lengths between the curves will be very short, entailing numerous 
zigzag curves, which are expensive to construct and maintain. 

592. Final Location.—The route being finally determined upon, 
it requires to be located. This consists in tracing the line, placing a 
stake at every 100 feet on the straight portions and at every 50 or 
25 feet on curves. At the tangent points of curves, and at points 
of compound and reverse curves, a larger and more permanent stake 
should be placed. Lest those stakes should be disturbed in the pro¬ 
cess of construction, their exact distance from several points out¬ 
side of the ground to be occupied by the road should be carefully 
measured and recorded in the note-book, that they may be replaced. 
The stakes above referred to show the position of the centre line 
of the road, and form the base line from which all ojierations of 
construction are carried on. Levels are taken at each stake, and 
cross-levels are taken at every change of longitudinal slope. 

593. Construction Profile.—The construction or working profile 
is made from the levels obtained on location. It should be drawn to 
a horizontal scale of 400 feet to the inch and a vertical scale of 20 
feet to the inch. Fig. 50 represents a portion of such a profile. 
The figures in column A represent the elevation of the ground at 
every 100 feet, or where a stake has been driven, above datum. 
The figures in column B are the elevations of the grade above 
datum. The figures in column C indicate the depth of cutting or 
height of fill; they are obtained by taking the difference between 
the level of the surface of the ground and the level of the road. 
The two straight parallel lines represent the grade of the road; the 
upper line is intended to show the upper surface of the road when 
finished, while the lower line represents what is termed the sub¬ 
grade or formation level. All the dimensions refer to the forma¬ 
tion level, to which the surface of the ground is to be formed to 
receive the road-covering. 

At all changes in the rate of incliration of the grade line a 
heavier vertical line should be drawn. 

594. Gradient.—The grade of a line is its longitudinal slope, 
and is designated by the proportion between its length and the 
difference of height of its two extremes. The ratio of these two 
quantities gives it its name: if the road ascends or falls one foot in 
every twenty feet of its length, it is said to have a grade of 1 : 20 




LOCATION OF COUNTRY ROADS. 


325 



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HIGHWAY CONSTRUCTION. 


or a 5 per cent grade. Grades are of two kinds, maximum and 
minimum. The maximum is the steepest which is to be permitted 
and which on no account is to be exceeded. The minimum is the 
least allowable for good drainage. (For method of designating 
grades see Table LXIII.) 

595. Determination of Gradients.—The maximum grade is fixed 
by two considerations, one relating to the power expended in as¬ 
cending, the other to the acceleration in descending the incline. 

There is a certain inclination, depending upon the degree of per¬ 
fection given to the surface of the road, which cannot be exceeded 
without a direct loss of tractive power. This inclination is that in 
descending which, at a uniform speed, the traces slacken; or which 
causes the vehicles to press on the horses; the limiting inclination 
within which this effect does not take place is the angle of repose. 

596. The angle of repose for any given road-surface can be 
easily ascertained from the tractive force required upon a level 
with the same character of surface. Thus if the force necessary 
on a level to overcome the resistance of the load is -fa of its weight, 
then the same fraction expresses the angle of repose for that sur¬ 
face. 

597. On all inclines less steep than the angle of repose a cer¬ 
tain amount of tractive force is necessary in the descent as well as 
in the ascent, and the mean of the two drawing forces, ascending 
and descending, is equal to the force along a level road. Thus on 
such inclines as much mechanical force is gained in the descent as 
is lost in the ascent. From this it might be inferred that when a 
vehicle passes alternately each way along the road, no real loss is 
occasioned by the inclination of the road; such is not, however, 
practically the fact with animal power, for whilst it is necessary in 
the ascending journey to have either a less or a greater number of 
horses than would be requisite if the road were entirely level, no 
corresponding reduction can be made in the descending journey. 
On inclines which are more steep than the angle of repose, the load 
presses on the horses during their descent, so as to impede their 
action, and their power is expended in checking the descent of the 
load; or if this effect be prevented by the use of any form of drag 
or brake, then the power expended on such drag or brake corre¬ 
sponds to an equal quantity of mechanical power expended in the. 
ascent, for which no equivalent is obtained in the descent. 






LOCATION OF COUNTRY ROADS. 


327 


598. Men and all animals can ascend steeper slopes than they 
can descend. A man walks slowly up-hill and quickly down-hill. 
A horse does the reverse: the steeper the ascent the faster, until 
fatigued, he attempts to travel, while in descending he moves at a 
slow trot which gradually subsides into a walk. Consequently the 
inclination which admits of high speed in descending practically 
controls the maximum grade. 

599. The maximum grade for a given road will depend (1) upon 
the class of traffic that will use it, whether fast and light, slow and 
heavy, or mixed, consisting of both light and heavy; (2) upon the 
character of the pavement adopted; and (3) upon the question of 
cost of construction. Economy of motive power and low cost of 
construction are antagonistic to each other, and the engineer will 
have to weigh the two in the balance. 

600. It is evident, therefore, that no fixed maximum gradient 
can be adopted in all situations. 

For fast and light traffic the grades should not exceed 2 per 
cent; for mixed traffic 3 per cent may be adopted; while for slow 
traffic combined with economy 5 per cent should not be exceeded. 
This grade is practicable but not convenient. 

601. The maximum grade for various paving materials is as 
follows: 

Stone blocks. all grades 

"Wood. .5 per cent 

Asphalt.21 

Brick. 5 

Broken stone.3 

602. The maximum grade adopted by the French engineers for 
macadamized roads is 5 per cent or 1 : 20. The maximum adopted 
by Telford was 1 : 30. 

603. It is obvious from Table LVIII that the smoother the road- 
surface the easier must be the grade. From this fact it has been 
deduced that on rough-surfaced roads steeper grades are permissi¬ 
ble than on smooth roads. This deduction is misleading. The 
force of gravity which has to be overcome is the same whether the 
road-surface be rough or smooth. The rough surface affords better 
foothold for the horse than the smooth surface, and thus assists 
him to exert his utmost force, but the great friction produced be¬ 
tween the wheels and the rough surface requires the expenditure 









328 


HIGHWAY CONSTRUCTION. 


of greater tractive force than would be required on a smooth sur¬ 
face. In practice there is no pavement which combines the oppo¬ 
site requirements of an even smooth surface for the wheels and a 
sufficiently rough surface affording good foothold for the horses, 
and a compromise of advantages must therefore be made in most 
cases. Where the extent and importance of the traffic will warrant 
the expense, stone trackways afford an excellent method for over¬ 
coming the disadvantage of smooth pavements on inclines. 

604. To Determine the Maximum Grade.—Let L denote the 
gross load to be hauled up an incline; /, the proportion of the 
resistance to the load on a level; S, the sine of the angle of the 
incline. Then (f S). L is the greatest resistance to be overcome 
in ascending the incline; and this should not exceed the greatest 
tractive force which the horse is capable of exerting. Let P be 
that force; then (/ -j- S) . L should not be greater than P, or S 

P 

should not be greater than This condition is essential and 

Lj 

fixes the maximum grade. 

To avoid excessive acceleration of speed in descending S should 
not exceed /. 

The proportion of the resistance/differs, as shown in Table LXI 
very much for different sorts of road coverings. It consists of two 
parts, one arising from friction and another arising from vibration, 
and increases with the velocity of transit. 

TABLE LXI. 

Value of /. 


Stone pavement... 0.015 = -fa 

Broken stone. 0.020 = 355- 

Gravel road. 0.067 = Ag- 

Soft sand and loose gravel. 0.143 = | 


605. Grade of Mountain Roads.—Although mountain roads are in 
general projected for slow traffic, yet as civilization and wealth in a 
country increase, roads adapted to the use of wheeled vehicles gradu¬ 
ally become used by an increasing amount of quick traffic. Ascend¬ 
ing grades of 1:20, 1:18, 1: 16 are too steep to permit of carriages 
drawn by horses ascending for any distance except at a foot-pace. 
Hack conveyances with relays at short distances can and do pro- 










LOCATION OF COUNTRY ROADS. 


329 


ceed more rapidly over hill roads with these grades, but such ser¬ 
vice is accompanied with a great amount of cruelty to the draught 
animals. Private horses are not called upon to work like hired 
hackneys, which are supposed to he able to do double the work they 
were capable of in their younger, and better, days; therefore, con¬ 
tinuous grades of 1: 16, 1 : 18, 1 : 20 means, as respects private 
quick traffic, its conversion into slow traffic. On the descent of 
such inclinations horses can only travel with safety at a slow 
trot, which probably subsides into a walk at the turns and when 
meeting other traffic. To ride down a slope of 5 per cent for a long 
distance is disagreeable. 

With a gradient of 4 per cent on a mountain road the slow 
traffic would be so well suited that ten miles continuous ascent 
could be surmounted without a halt or undue exertion on the part 
of the draught animals. Such a grade would not reduce quick 
traffic to a walk throughout an ascent, and it would permit of 
horses descending with safety at six to eight miles an hour. 

606. Minimum Grade.—From the previous considerations it 
would appear that an absolutely level road was the one to be sought 
for, but this is not so; there is a minimum or least allowable grade 
which the road must not fall short of, as well as a maximum one 
which it must not exceed. If the road was perfectly level in its 
longitudinal direction, its surface could not be kept free from 
water without giving it so great a rise in its middle as would ex¬ 
pose vehicles to the danger of overturning. 

The minimum grade established in France by the Corps des 
Ponts et Chaussees is .008, or 1 in 125; this may be adopted as 
the minimum, and in a perfectly level country the road should 
be artificially formed into gentle undulations approximating this 
minimum limit. 

607. Undulating Grades.—From the fact that the power re¬ 
quired to move a load at a given velocity on a level road is 
decreased on a descending grade to the same extent that it is in¬ 
creased in ascending the same grade, it must not be inferred that 
the animal force expended in passing alternately each way over a 
rising and falling road will gain as much in descending the several 
inclines as it will lose in ascending them. Such is not the case. 
The animal force must be sufficient, either in power or number, to 
draw the load over the level portions and up the steepest inclines 





330 


HIGHWAY CONSTRUCTION. 


of the road, and in practice no reduction in the number of horses 
can be made to correspond with the decreased power required in 
descending the inclines. 

The popular theory that a gentle undulating road is less fatigu- 


TABLE LXII. 

Different Methods of Designating the Same Grades. 


American Method, 
Feet per 100 feet. 

English Method. 

Feet per Mile. 

Angle with the 
Horizon. 

i 

1 : 400 

13.2 

0 C 

8' 

36" 

i 

1 : 200 

26.4 

0 

17 

11 

t 

1 : 150 

39.6 

0 

22 

55 

1 

1 : 100 

52.8 

0 

34 

23 

n 

1 : 80 

66 

0 

42 

58 

u 

1 : 66f 

79.2 

0 

51 

28 

it 

1 : 5?i 

92.4 

1 

0 

51 

2 

1 : 50 

105.6 

1 

8 

6 

2* 

1 : 44i 

118.8 

1 

17 

39 

2i 

1 : 40 

132 

1 

25 

57 

2} 

1:361 

145.2 

1 

34 

22 

3 

1 : 331 

158.4 

1 

43 

08 

3 i 

1 : 30| 

171.6 

1 

51 

42 

3 £ 

1 :28 £ 

184.8 

2 

0 

16 

3| 

1 : 26} 

198 

2 

8 

51 

4 

1 : 25 

211.2 

2 

17 

26 

4i 

1 : 231 

224.4 

2 

26 

10 

4* 

1 : 221 

237.6 

2 

34 

36 

4f 

1 : 21 

250.8 

2 

43 

35 

5 

1 : 20 

264 

2 

51 

44 

6 

1: 18} 

316 8 

3 

26 

12 

7 

1 : 14} 

369.6 

4 

0 

15 

8 

1 : 121 

422.4 

4 

34 

26 

9 

1 : 111 

475.2 

5 

8 

31 

10 

1 : 10 

528 

5 

42 

37 


ing to horses than one which is perfectly level is erroneous. The 
assertion that the alternations of ascent, descent, and levels call into 
play different muscles, allowing some to rest while others are ex¬ 
erted, and thus relieving each in turn, is demonstrably false, and 
contradicted by the anatomical structure of the horse. Since this 
doctrine is a mere popular error, it should be utterly rejected, not 
only because false in itself, but still more because it encourages 
the building of undulating roads, and this increases the labor and 
cost of transportation upon them. 

608. Level Stretches.—On long ascents it is generally recom¬ 
mended to introduce level or nearly level stretches at frequent in¬ 
tervals in order to rest the animals. These are objectionable when 













LOCATION OF COUNTRY ROADS. 


331 





they cause loss of height, and animals will be more rested by halt¬ 
ing and unharnessing for half an hour than by travelling over a 
level portion. The only case which justifies the introduction of 
levels into an ascending road is where such levels will advance the 
road towards its objective point; where this is the case there will 
be no loss of either length or height, and it will simply be exchang¬ 
ing a level road below for a level road above. 

609. Establishing the Grade. —When the profile of a proposed 
route has been made, a grade line is drawn upon it (usually in red) 
in such a manner as to follow its general slope, but to average its 
irregular elevation and depressions. 

If the ratio between the whole distance and the height of the 
line is less than the maximum grade intended to be used, this line 
will be satisfactory; but if it be found steeper, the cuttings or the 
length of the line will have to be increased: the later is generally 
preferable. 

610. The apex or meeting point of all curves should be rounded 
off by a vertical curve shown in Figs. 51 to 53. 

The formula for these curves is given in Art. 935. 

EXAMPLES OF THE APPLICATION OF VERTICAL CURVES. 




Figs. 51 to 53. 









CHAPTER XII. 


WIDTH AMD TRANSVERSE CONTOUR. 

611 . A road should be wide enough to accommodate the traffic 
for which it is intended, and should comprise a wheelway for 
vehicles and a space on each side for pedestrians. 

612 . The wheel way of country highways need be no wider than 
is absolutely necessary to accommodate the traffic using it; in many 
places a track wide enough for a single team is all that is necessary. 
But the breadth of the land appropriated for highway purposes 
should be sufficient to provide for all future increase of traffic. 
The wheelwaysof roads in rural sections should be double; that is, 
one portion paved (preferably the centre) and the other left with 
the natural soil. The latter if kept in repair will for at least one 
half the year be preferred by teamsters. 

613 . The minimum width of the paved portion, if intended to 
carry two lines of travel, is fixed by the width required to allow 
two vehicles to pass each other safely. This width is 16 feet. If in¬ 
tended for a single line of travel, 8 feet is sufficient but suitable 
turnouts must be provided at frequent intervals. The most eco¬ 
nomical width for any roadway is some multiple of eight. 

614 . Wide roads are the best; they expose a larger surface to the 
drying action of the sun and wind, and require less supervision than 
narrow ones. Their first cost is greater than narrow ones, and that 
nearly in the ratio of the increased width. 

615 . The cost of maintaining a mile of road depends more 
upon the extent of the traffic than upon the extent of its surface, 
and unless extremes be taken the same quantity of material will be 
necessary for the repair of the road whether wide or narrow which 
is subjected to the same amount of traffic. The cost of spreading 
the materials over the wide road will be somewhat greater, but 
the cost of the materials will be the same. On narrow roads the 
traffic, being confined to one track, will wear more severely than if 
spread over a wider surface. 

616 . The width of land appropriated for road purposes varies in 
the United States from 49 \ to 66 feet; in England and France 

332 


WIDTH AND TRANSVERSE CONTOUR. 


333 


from 26 to GG feet. And the width or space macadamized is also 
subject to variation; in the United States the average width is 1G 
feet; in France it varies between 1G and 22 feet; in Belgium 85 feet 
seems to be the regular width, while in Austria it varies from 14A 
to 26^ feet. 

Figs. 85-92, page 342, show the subdivision of the roadway into 
wheelway, sidewalks, and ditches. 

617. Width of Mountain Roads.—Mountain roads should be pro¬ 
portioned in width to the amount of traffic; they should be neither 
too wide nor too narrow. If of excessive width, the cost of con¬ 
struction is increased; if too narrow, traffic will be interrupted by 
blockades. An economical width is 24 feet, and the stone covering 
should extend from gutter to guttre. If the center only is covered, 
the road will soon be destroyed, as, by reason of the curves on a 
mountain side predominating over straight reaches, the traffic will 
hug; either one side of the road or the other. 

Table LXIII shows the number of acres required per mile for 
different widths of roadway. 

TABLE LXIII. 


Acres required per Mile for Different Widths of Roadway. 


Width. 

Feet. 

Acres 
per mile. 

Width. 

Feet. 

Acres 
per mile. 

Width. 

Feet. 

Acres 
per mile. 

Width. 

Feet. 

A cres 
per mile. 

1 

Width. 

Feet. 

Acres 
per mile. 

4 

.033 

19 

2.30 

40 

4.85 

59 

7.15 

80 

9.70 

4 

.066 

20 

2.42 

41 

4 97 

60 

7.27 

81 

9.82 

1 

.121 

21 

2.55 

414 

5.00 

61 

7.39 

82 

9.94 

2 

.242 

22 

2.67 

42 

5.09 

62 

7 52 

824 

10.00 

3 

.364 

23 

2.79 

43 

5.21 

63 

7.64 

83 

10.06 

4 

.485 

24 

2.91 

44 

5.33 

64 

7.76 

84 

10.18 

5 

.606 

24J 

3.00 

45 

5.45 

65 

7.88 

85 

10.30 

6 

727 

25 

3.03 

46 

5.58 

66 

8.00 

86 

10.42 

n 

.848 

26 

3.15 

47 

5.70 

67 

8.12 

87 

10.54 

8 

.970 

27 

3.27 

48 

5.82 

68 

8.24 

88 

10.66 

84 

1.00 

28 

3.39 

49 

5.94 

69 

8.36 

89 

10.78 

9 

1.09 

29 

3 52 

494 

6.00 

70 

8.48 

90 

10.90 

10 

1.21 

30 

3.64 

50 

6.06 

71 

8.61 

9 Of 

11.00 

11 

1.33 

31 

3.76 

51 

6.18 

72 

8.73 

91 

11.03 

12 

1.46 

32 

3.88 

52 

6.30 

73 

8.85 

92 

11.15 

13 

1.58 

33 

4.00 

53 

6.42 

74 

8.97 

93 

11.27 

14 

1.70 

34 

4.12 

54 

6.55 

744 

9.00 

i 94 

11.39 

15 

1.82 

35 

4.24 

55 

6.67 

75 

9.09 

95 

11.51 

16 

1.94 

36 

4.36 

56 

6.79 

76 

9.21 

96 

11.63 

16* 

17 

2.00 

37 

4.48 

57 

6.91 

77 

9.33 

97 

11.75 

2.06 

38 

4.61 

57| 

7.00 

78 

9.45 

98 

11.87 

18 

2.18 

39 

4.73 

58 

7.03 

79 

9.58 

99 

'00 

12.00 

12.12 























































HIGHWAY CONSTRUCTION. 


0 0/4 


613. Transverse Contour.—The centre of all roadways should 
be higher than the sides. The object of this is to facilitate the flow 
of the rain-water to the gutters. Where a good surface is main¬ 
tained a very moderate amount of rise is sufficient for this purpose. 
Earth roads require the most and asphalt the least. The rise should 
bear a certain proportion to the width of the carriageway. The 
most suitable proportions for the different paving materials is shown 
in the following table: 


TABLE LXIV. 

Amount of Transverse Rise required for Different Pavements. 


Kind of Surface. 

Earth . 

. .Rise at centre . 

Proportion of the 
Carriageway Width. 

Gravel . 

t ( 


Broken stone. 

a 

l 

Stone blocks. . 

* i 


Wood. 

a 

1 

Brick. 

€ ( 

i 

Asphalt. 

( « 

1 


619. Form of Transverse Contour.—All authorities agree that 
the form should be convex, but they differ in the amount and 
form of the convexity. Circular arcs, two straight lines joined by a 
circular arc and ellipses all have their advocates, but the best form 
for streets will be found to be a parabolic curve starting from the 
edge of the gutter next the carriageway or one foot from the 
curb line. Fig. 54 shows this form, which is obtained in the fol¬ 
lowing manner: Divide the ordinate or the width between the 
edge of the gutter and the centre of the street into 10 equal parts, 
and raise perpendiculars the length of which will be determined 
by multiplying the rise at the center by the respective number of 
each perpendicular in the diagram. The amounts thus obtained 
can be added to the rod readings, and the stakes set at the proper 
distance across the street with their tops at this level will give the 
true curve. 

620. For country roads a curve of suitable convexity may be 
obtained as follows: Give -J of the total rise at i the width from 
the centre to the side, and § of the total rise at i the width (Fig. 55). 

621. Excessive height and convexity of cross-section contract 
the width of the wheelway, by concentrating the traffic at the 


















WIDTH AND TRANSVERSE CONTOUR. 


335 


TRANSVERSE CONTOUR OF STREETS AND ROADS. 


♦ 

1 4 > 

\ 

• V 




21 

o 



73 

CO 

m 

co 

m 

o 

H 

O 

z 

o 

~n 

73 

o 

> 

o 


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OFAB 


OFAB; 


Af’B 














33 6 


HIGHWAY CONSTRUCTION. 


centre, that being the only part where a vehicle can run upright. 
The force required to haul vehicles over such cross-sections is 
increased, because an undue proportion of the load is thrown upon 
two wheels instead of being distributed equally over the four. 
The continual tread of horses’ feet in one track soon forms a 
depression which holds water, and the continuous travel of vehicles 
in one track soon wears ruts which retain water, and the surface is 
not so dry as with a flatted section, which allows the traffic to dis¬ 
tribute itself over the whole width. 

622. Sides formed of straight lines are also objectionable. 
They wear hollow, retain water, and defeat the object sought by 
raising the centre. 

623. Concave Form.—In Triest, Austria, the early pavements 
were laid concave, i.e., inclining to the middle, along which, under 
the surface-canals or sewers extended with gratings at intervals for 
the admission of surface-drainage. The same method, but with 
open channels through the centre, is practised in several South 
American towns. Experience has proved that this plan is not 
desirable or convenient for traffic. 

624. The required convexity should be obtained by rounding 
the formation surface, and not by diminishing the thickness of the 
covering at the sides. 

625. On hillside and mountain roads it is generally recom¬ 
mended that the surface should consist of a single slope inclining 
inwards. There is no reason for or advantage gained by this 
method. The form best adapted to these roads is the same as for 
a road under ordinary conditions, viz., that described in Art. 619. 

626. With a roadway raised in the centre and the rain-water 
draining off to gutters on each side, the drainage will be more 
effectual and speedy than if the drainage of the outer half of the 
road has to pass over the inner half. The inner half of such road 
is usually subjected to more traffic than the outer half. If formed 
of a straight incline, this side will be worn hollow and retain water. 
The inclined flat section never can be properly repaired to with¬ 
stand the traffic. Consequently it never can be kept in good order, 
no matter how constantly it may be mended. It is always below 
par. When heavy rain falls it is seriously damaged. 





CHAPTER XIII. 


EARTH-WORK. 

627. Earth-work.—The term “ earth-work ” is applied to all the 
operations performed in the making of the excavations and em¬ 
bankments to prepare them for receiving the road-covering. In 
its widest sense it comprehends work in rock as well as in the 
looser material of the earth’s crust. 

628. Equalizing Earth-work is a term applied to the process of 
so adjusting the formation or sub-grade level of an inter led work 
that the earth from the cuttings shall be as nearly as possible 
sufficient to make the embankments and no more. The art of 
making this adjustment by the eye upon a profile of the ground 
with sufficient accuracy is soon acquired by practice. In most 
cases it is essential to economy in the cost of the work. For any sur¬ 
plus of embankment over cutting must be made up by borrowing,, 
and the earth from any surplus of cutting over embankment must 
be wasted, both of these operations involve additional cost for labor 
and land. But cases sometimes occur in which it is more economi¬ 
cal to make an embankment from borrow-pits close at hand than 
to bring the necessary material from a far-distant cutting on the 
line of the works, or in which it is more economical to waste part 
of the material from a cutting than to send it to a far-distant 
embankment on the line of the works, and these points must be 
decided by the engineer to the best of his judgment in each par¬ 
ticular case. 

629. Transverse Balancing.—When the road lies along the side 
of a hill, so that it is partly in excavation and partly in embank¬ 
ment, it is necessary to so place its centre line that these two parts 
of cross-section may balance. When the ground has a uniform 
slope the desired end would be obtained (if the side slopes were the 
same for excavation and embankment and if no shrinkage existed), 

337 


338 


HIGHWAY CONSTRUCTION. 


by locating the centre line of the road upon the surface of the 
ground. 7 n other cases, as when the side of the excavation slopes 
1 to 1 and that of the embankment 2 to. 1, a formula to determine 
the position of the centre line may be readily established. 

630. If earth be wanted for a neighboring embankment, the 
amount of excavation may be easily increased by moving the 
centre of the road farther into the hill, with the additional advan¬ 
tage of lessening its liability to slip. The line may be thus 
changed on the map according to the notes of the cross-section in 
the level book, and be subsequently moved by a corresponding 
quantity on the ground. 

631. When the slope of the ground is very steep the transverse 
balance must be disregarded and the road made chiefly in excava¬ 
tion, to avoid the insecurity of a high embankment. 

632. Borrow-pits.—When the excavations on the line of the 
road do not furnish sufficient material for the embankments, the 
deficiency is obtained either by widening the excavations, or from 
an excavation termed a “ borrow-pit,” made in the vicinity of the 
embankment. 

633. Spoil-banks.—If the excavations furnish more material 
than is required for the embankments, the excess is generally 
deposited in a convenient place on the land adjoining the excava¬ 
tion, in banks termed “ spoil-banks.” 

Both these cases are expensive and objectionable. It is there¬ 
fore very desirable to make the excavation and embankment 
"balance” each other. If the calculations show much disparity in 
the two amounts, the location of the line should be changed in 
some way so as to effect the desired equality. 

634. The equalization must, however, be restrained within 
certain limits, for it should evidently be abandoned when, in order 
to form sufficient excavation to make the embankment, it would 
be necessary to go to such a distance that the cost of transport 
would exceed the cost of borrowing for the banks and wasting the 
distant excavation in spoil-banks. 

635. The comparison of the price of transport with that of 
excavation and land will therefore determine the distance within 
which the balancing must be established. 

636. The form to be given to the borrow-pits and spoil-banks will 
depend in a great degree upon the locality ; they should as far as 



EARTH-WORK. 


339 


practicable be located so that the cost of removal of the earth shall 
be the least possible. 

637. Staking out Borrow-pits.—Borrow-pits should be staked out 
by the engineer and their contents calculated, unless the contractor 
is to be paid by embankment measurements. A number of cross¬ 
profiles are taken of the original surface, and (on the same lines) 
on the bottom of the pit, after it is excavated, which furnish the 
depth of cutting at each required point. Borrow-pits should be 
regularly excavated so that they may not present an unsightly ap¬ 
pearance when abandoned. 

638. Shrinkage.—The equality recommended must be taken 
with an important qualification, dependent upon the fact that 
earth transferred from excavation to embankment shrinks, or 
settles so as to occupy less space in the bank than it did in its 
natural state. 

Kock, on the contrary, occupies more space when broken. 

639. In estimating the relative amounts of excavation and em¬ 
bankment required, allowance must be made for difference in the 
spaces occupied by the material before excavation and after it is 
settled in embankment. The shrinkage of the different materials 
is about as follows : 


Gravel.8 per cent 

Gravel and sand. 9 “ 

Clay and clay earths.19 

Loam aud light sandy earths.12 

Loose vegetable soil.15 “ 

Puddled clay.25 


Eock, on the other hand, increases in value by being broken up, 
and does not settle again into less than its original bulk. The in¬ 
crease may be taken at fifty per cent. 

Thus an excavation of loam measuring 1000 cubic yards will 
form only about 880 cubic yards of embankment, or an embankment 
of 1000 cubic yards will require about 1120 cubic yards measured 
in excavation to make it. A rock excavation measuring 1000 yards 
will make from 1500 to 1700 cubic yards of embankment, depend¬ 
ing upon the size of the fragments. 

640. The lineal settlement of earth embankments will be 
about in the ratio given above; therefore either the contractor 
should be instructed in setting his poles to guide him as to the 









340 


HIGHWAY CONSTRUCTION. 


height of grade on an earth embankment to add the required per¬ 
centage to the fill marked on the stakes, or the percentage may be 
included in the fill marked on the stakes. In rock embankments 
this is not necessary. 

641. Failure of Earth-work.—The failure of earth-work is due 
to the slipping or sliding of its parts on each other, and its 
stability arises from resistance to the tendency so to slip. 

In solid rock, that resistance arises from the elastic stress of the 
material, when subjected to a shearing force ; but in the mass of 
earth, as commonly understood, it arises partly from the friction 
between the grains, and partly from their mutual adhesion; which 
latter force is’considerable in some kinds of earth, such as clay, 
especially when moist. 

But the adhesion of earth is gradually destroyed by the action 
of air and moisture, and of the changes of the weather, and especi¬ 
ally by alternate frost and thaw ; so that its friction is the only 
force which can be relied upon to produce permanent stability. 

642. The temporary additional stability, however, which is 
produced by adhesion, is useful in the execution of earth-work, by 
enabling the sides of a cutting to stand for a time with a vertical 
face for a certain depth below its upper edge. That depth is 
greater, the greater the adhesion of the earth as compared with its 
heaviness ; it is increased by a moderate degree of moisture, but 
diminished by excessive wetness. 

The following are some of its values : 


Earth. 

Clean dry sand and gravel from. 

Moist sand and ordinary surface mould from 

Clay (ordinary) from. 

Compact gravel from. 


Greatest depth of 
tem. vert. face. 

... 0 to 1 foot. 

... 3 “ 6 feet 
...10 “ 16 “ 
...10 “ 15 “ 


643. One of the effects of the temporary stability due to adhesion 
is seen in the figure of the surface left after a “ slip ” has taken 
place in earth-work. That surface is not a uniform slope, inclined 
at the angle of repose, but is concave in its vertical section, being 
vertical at its upper edge, and becoming less and less steep down¬ 
wards. It is not capable, however, of preserving that figure ; for 
the action of the weather, by gradually destroying the adhesion of 
the earth, causes the steep upper part of the concave face to crumble 







EARTH-WORK. 


341 


•down, so that the whole tends to assume a uniform curved slope in 
the end. 

644. The Permanent Stability of earth, which is due to friction 
alone, is sufficient to maintain the side either of an embankment 
or of a cutting at a uniform slope, whose inclination to the horizon 
is the angle of repose, or angle whose tangent is the coefficient of 
friction. This is called the natural slope of the earth. The cus¬ 
tomary mode of describing the slope of earth-work is to state the 
ratio of the horizontal breadth to its vertical height, which is the 
reciprocal of the tangent of the inclination. 

645. The angles of repose for different earths are given in 
Table XLY. But for all practical purposes it may be said that 
all earths, sand and gravel, stand at a slope of 33 degrees 41 
minutes, or 1^ to 1. If the slopes of an excavation in sand are to 
be left unprotected by sodding, they should be given a slope of 24 
to 1. The ratio of slopes, their angles and length, are given in 
Table XLYI. 


TABLE LXV. 

Natural Slopes of Earths (with Horizontal Line). 


Gravel (average).40 degrees 

Dry sand . 38 

Wet “ .22 

Vegetable earth.28 

Compact earth.50 

Shingle. 39 

Rubble.45 

Clay (well drained) .45 

“ (wet).13 


TABLE LXYI. 

Lengths and Angles of Slopes. 


Slope. 

Angle 

with Horizon 

Length. 

(Height taken as 1.00.) 

Slope. 

Angle 

with Horizon 

Length. 

(Height taken as 1.00). 

4 : 1 

75° 58' 

1.0307 

u 

1 

33° 41' 

1.802 

4 : 1 

63 26 

1.118 

H 

1 

29 44 

2.016 

4 : 1 

53 8 

1.25 

2 

1 

26 34 

2.236 

1 : 1 

45 0 

1.4142 

3 

1 

18 26 

3.162 

H:1 

38 40 

1.6 

4 

1 

14 2 

4.124 

































342 


HIGHWAY CONSTRUCTION. 


646. The inclinations generally given in practice to the various, 
materials are as follows: 

Loose earth, loam aiul gravel.1£ to 1 


Sand...2 “ 1 

Soft greasy clay.3 “ 1 

Hock (sound).0£ “ 1 


647. Effect of Moisture.—The presence of moisture in earth to 
an extent just sufficient to expel the air from its crevices seems to 
increase its coefficient of friction | slightly; but any additional 
moisture acts like a lubricant in diminishing friction, and tends 
to reduce the earth to a semi-fluid condition, or to the state of 
mud. In this state, although it has some cohesion, or viscidity,, 
which resists rapid alteration of form, it has no frictional stability; 
and its coefficient of friction and angle of repose, are each of 
them null. 

Hence it is obvious that the frictional stability of earth depends 
to a great extent on the ease with which the water that it occasion¬ 
ally absorbs can be drained way. The safest materials for earth¬ 
work are fragments of rock, shingles, gravel, and clean sand; for 
these materials allow water to pass through without retaining more 
of it than is beneficial. The cleanest sand, however, may be made 
completely unstable and reduced to the state of “ quick sand ” if 
it is contained in a basin of water-holding materials so that water 
mixed amongst its particles cannot be drained off. 

The property of retaining water and forming a paste with it 
belongs specially to clay, and to earths of which clay is an ingre¬ 
dient. v Such earths, how hard and firm soever they may be when 
first excavated, are gradually softened, and have both their fric¬ 
tional stability and their adhesion diminished by exposure to the 
air. In this respect mixtures of sand and clay are the worst; 
for the sand favors the access of water, and the clay prevents its 
escape. 

The properties of earth with respect to adhesion and friction 
are so variable that the engineer should never trust to tables or to 
information obtained from books to guide him in designing earth¬ 
works, when he has it in his power to obtain the necessary data 
either by observation of existing earth-works in the same stratum 
or by experiment. 







EARTH-WORK. 


343 


648. Inclination of Side Slopes.—The proper inclination for the 
side slopes of cuttings and embankments depends on the nature of 
the soil and the action of the atmosphere and of internal moisture 
upon it. 

“ In common soils, as ordinary garden earth formed of a mixture 
of clay and sand, compact clay, and compact stony soils, although 
the side slopes would withstand very well the effects of the weather 
with a steeper inclination, it is best to give them two base to one 
perpendicular, as the surface of the roadway will, by this arrange¬ 
ment, be well exposed to the action of the sun and air, which will 
cause rapid evaporation of the moisture of the surface. Pure sand 
and gravel may require a greater slope according to circumstances. 
In all cases where the depth of the excavation is great the base of 
the slope should be increased. 

“ In excavations through solid rock, which does not disintegrate 
on exposure to the atmosphere, the side might be perpendicular; 
but as this would exclude in a great degree the action of the sun 
and air, which is essential to keeping the road-surface dry and in 
good order, it is necessary to make the side slopes with an inclina¬ 
tion varying from one base to one perpendicular, to one base to 
two perpendicular, or even greater, according to the locality; the 
inclination of the slopes on the south side in northern latitudes 
being the greater, to expose better the road-surface to the sun-rays. 

“ The slaty rocks generally decompose rapidly on the surface 
when exposed to moisture and the action of frost. The side 
slopes in rocks of this character may be cut into steps and then be 
covered by a layer of vegetable mould sown in grass-seed, or else 
the earth may be sodded in the usual way.” 

649. Form of Side Slopes.—The natural, strongest, and ultimate 
form of earth slopes is a concave curve, in which the flattest portion 
is at the bottom. This form is very rarely given to the slopes in 
constructing them; in fact, the reverse is often the case, the slopes 
being made convex, thus -saving excavation for the contractor and 
inviting slips. 

In cuttings exceeding 10 feet in depth the forming of concave 
slopes will materially aid in preventing slips, and in any case they 
will reduce the amount of material which will eventually have to 
be removed when cleaning up. Straight or convex slopes will con¬ 
tinue to slip until the natural form is attained. 




344 


HIGHWAY CONSTRUCTION. 


A revetment or retaining wall at the base of a slope will save 
excavation. 

In excavations of considerable depth, and particularly in soils 
liable to slips, the slope may be formed in terraces, the horizontal 
offsets or benches being made a few feet in width with a ditch on 
the inner side to receive the surface-water from the portion of the 
side slope above them. These benches catch and retain earth that 
may fall from the slopes above them. (See Fig. 56.) 



650. Covering of Slopes.—It is not usual to employ any artificial 

means to protect the surface of the side slopes from the action of 
the weather; hut it is a precaution which in the end will save much 
labor and expense in keeping the roadways in good order. The 
simplest means which can be used for this purpose consists in cov¬ 
ering the slopes with good sods, or else with a layer of vegetable 
mould about four inches thick, carefully laid and sown with grass- 
seed. These means are amply sufficient to protect the side slopes 
from injury when they are not exposed to any other causes of 
deterioration than the wash of the rain and the action of frost on 
the ordinary moisture retained by the soil. 

A covering of brushwood or a thatch of straw may also be used 
with good effect; but from their perishable nature they will require 
frequent renewal and repairs. 

“ Where stone is abundant a small wall of dry stone may be 
constructed at the foot of the slopes to prevent any wash from them 
being carried into the ditches/’ 

651. Slips.—“The stratified soils and rocks in which the strata 
have a dip or inclination to the horizon are liable to slips, or to 
give way by one stratum becoming detached and sliding on another. 












EARTH-WORK. 


345 


which is caused either from the action of frost or from the pres¬ 
sure of water which insinuates itself between the strata. The 
worst soils of this character are those formed of alternate strata of 
clay and sand, particularly if the clay is of a nature to become 
semi-fluid when mixed with water. The best preventives that 
can be resorted to in these cases are to adopt a system of thorough 
drainage, to prevent the surface-water of the ground from running 
down the side slopes, and to cut off all springs which run towards 
the roadway from the side slopes. The surface-water may be cut 
off by means of a single ditch, termed a catch-water ditch, exca¬ 
vated a few feet back from the crest of the slope, so that it inter¬ 
cepts the water before it reaches the slope of the excavation, and 
convey it off to the most convenient natural water-courses. Usu¬ 
ally this ditch will be required only on the up-hill side of the road; 
for in almost every case it will be found that the side slope on the 
down-hill side is, comparatively speaking, but slightly affected by 
the surface-water. 

“ Where slips occur from the action of springs, it frequently 
becomes a very difficult task to secure the side slopes. If the 
sources can be easily reached by excavating into the side slopes, 
drains formed of layers of fascines or brushwood may be placed to 
give an outlet to the water and prevent its action upon the side 
slopes. The fascines may be covered on top with good sods laid 
with the grass side beneath, and the excavation made to place the 
drain filled in with good earth well rammed. Drains formed 
of broken stone or Cobbles covered in like manner on top with a 
layer of sod to prevent the drain from becoming choked with earth 
may be used under the same circumstances as fascine drains. 
Where the sources are not isolated and the whole mass of the soil 
forming the side slopes appears saturated, the drainage may be 
effected by excavating trenches a few feet wide at short intervals 
to the depth of some feet into the side slopes, and filling them with 
boulders or broken stone, dr else a general drain of stone may be 
made throughout the whole extent of the side slope by excavating 
into it. When this is deemed necessary it will be well to arrange 
the drain like an inclined retaining-wall with buttresses at inter¬ 
vals projecting into the earth farther than the general mass of the 
drain. The front face of the drain should, in this case, also be 
covered with a layer of sods with the grass side next to the stones 




34G 


HIGHWAY CONSTRUCTION'. 


forming the drain, and upon this a layer of good earth should bo 
compactly laid to form the face of the side slopes. The drain need 
only be carried high enough above the toe of the side slope to tap 
all the sources, and it should be sunk sufficiently below the roadway 
to give it a secure footing.” 

“ The drainage has been effected, in some cases, by sinking 
wells or shafts at some distance behind the side slopes, from the 
top surface to the level of the bottom of the excavation and lead¬ 
ing the water which collects in them by pipes into the drains at 
the foot of the side slopes. In others a narrow trench has been 
excavated, parallel to the axis of the road, from the top surface to 
a sufficient depth to tap all the sources which flow towards the 
side slope, and a drain formed either by filling the trench wholly 
with stone or else by arranging an open conduit at the bottom to 
receive the water collected, over which a layer of brushwood is 
laid, the remainder of the trench being filled with stone.” 

652. Embankments. —The best materials for embankments are 
those whose frictional stability is the greatest and the most perma¬ 
nent, such as fragments of rock, shingle, gravel, and clean sand. 
Clay forms safe embankments, provided it is dry, or nearly dry, 
when laid down. Wet clay, vegetable mould, and mud are unfit for 
use in embankments; so also is peat, except when dry. 

653. An embankment may be made in three ways: (1) In one 
layer. (2) In two or more thick layers. (3) In thin layers. 

(1) In One Layer .—This being the cheapest and quickest 


B 



method consistent with stability, is that followed in all earth-works in 
which there is no special reason requiring it to be performed by the 
other methods, in Fig. 57 BAG 1 represents the natural surface of 






EARTH-WORK. 


347 


the ground; DA, part of the base of a cutting; AEG, an embank¬ 
ment the construction of which is carried forward in the direction 
AE of its full width and height (including a sufficient allowance 
for settlement), by running dump-carts on temporary tracks from 
the cutting along the top of the embankment, and tipping them 
at E, so that the earth runs down and spreads itself over the sloping 
end EC of the bank, which is called the “tip.” Embankments 
formed in this manner are deficient in compactness, for the par¬ 
ticles of earth which are emptied from the top of the bank will 
temporarily stop in their descent at the point of the slope at which 
the friction becomes sufficient to balance their gravity; and when 
more earth conies upon them, they will give way and slide lower 
down, causing the portions above them to slip and crack, and thus 
delay for a long time the complete consolidation. 

Tipping or dumping the earth over the sides of banks made in 
the above manner should not be allowed, for the earth so dumped 
is liable afterwards to slip off. 

The solidity of embankments formed in the above manner may 
be increased by filling from the sides towards the centre in order 
that the earth may arrange itself in layers with a dip from the sides 
inwards. 



FIG. 58. CROSS-SECTION OF EARTH EMBANKMENT, 
SHOWING METHOD OF PLACING THE LAYERS. 

As the rapidity with which a bank can be made by this method 
is dependent upon the number of tipping or dumping points, it is 
usual to form the bank wider at top and narrower at the bottom 
than it is finally to be, maintaining of course the requisite area of 
cross-section; the excess at the top (the angles AB, Fig. 59) be¬ 
ing subsequently moved down to the bottom, thus securing the 
r^ aired width of base and inclination of side slopes. 

jt. 

It is mistaken economy to first form embankments narrow and 







348 


HIGHWAY CONSTRUCTION - . 


afterwards widen them by lateral additions, for the new material 
will never unite perfectly with the old. 

(2) In Thick Layers .—This process has been used in some em¬ 
bankments of great height. It consists in completing the con¬ 
struction of the embankment up to a certain height by the process 
of end-dumping already described; leaving that layer for a time 
to settle, and then making a second layer in the same way, and so 



on. It involves much additional time and labor, and is seldom 
employed. It is, however, useful in making embankments of hard 
clay or shale, which, when first dumped, consists of angular lumps 
that lie with vacant spaces between them and do not form a com¬ 
pact mass until partially softened and broken down by the action 
of air and moisture. 

(3) In Thin Layers .—This process consists in spreading the 
earth in horizontal layers of from 9 to 18 inches deep, and rolling 
or ramming each layer so as to make it compact and firm before 
laying down the next layer. Being a tedious and costly process, 
it is used in special cases only, of which the principal are the filling 
in behind retaining walls, behind wings and abutments of bridges 
and culverts, and over their arches. 

654. Side Slopes of Embankments. —In forming the embank¬ 
ments the side slopes should be made with a greater inclination 
than that which the earth naturally assumes, for the purpose of 
giving them greater durability, and to prevent the width of the 
top surface along which the roadway is made from diminishing by 
every change in the side slopes, as it would were they made with 
the natural slope. To protect the side slopes more effectually 
they should be sodded, or sown in grass-seed, and the surface water 
of the top should not be allowed to run down them, as it would 
soon wash them into gulleys and destroy the embankment. In 










EARTH-WORK. 


349 


localities where stone is plentiful a sustaining wall of dry stone 
may be advantageously substituted for the side slopes. 

The toe or foot of embankments has a tendency to spread; this 
may be resisted by excavating a small trench along the toe, or by 
buttressing with a low stone wall. 

655. Drainage of Embankments.—The only drains required for 
embankments over good ground are the ordinary side ditches, with 
occasional culverts to convey the water from them into the natural 
water-courses. When springs are crossed, stone drains or culverts 
may be built to carry the water clear of the embankment. 

656. Embankments over Plains.—When a roadway is carried 
across an extensive plain, it is almost always necessary, in order to 
keep its surface dry, that it should be raised above the general 
level of the ground; and where inundations occur, the requisite 
height may be considerable. In Fig. 60, A represents a cross-sec- 



FiG. 60. SECTION OF EMBANKMENTS OVER PLAINS. 

tion of an embankment for this purpose, the materials for which 
are obtained by digging a pair of trenches alongside of it. These 
trenches, by collecting surface-water and discharging it into the 
nearest river or other main drainage channel, tend to shorten the 
duration of floods in the neighborhood of the line. 

657. Embankments across Marshes.—When the ground is so- 
soft that an embankment made in the ordinary way would sink in 
it, different expedients are to be employed according to the kind 
and degree of difficulty to be overcome. The following list of 
expedients is arranged in the order of an increasing scale of dif¬ 
ficulty: 

(1) By digging side drains parallel to the site of the intended 
embankment, the firmness of the natural ground may be increased. 

(2) If the material of the natural ground has a definite angle 
of repose, though much flatter than that of the material of the 
embankment, the slopes of the embankment may be formed to the 
same angle, thus giving it a broader foundation than it would have 
with its own natural slope. 














HIGHWAY CONSTRUCTION. 


*> 

<L> 


50 


(3) A foundation may be made for the embankment by digging 
a trench and filling it with a stable material. 

(4) The ground may be compressed and consolidated by driving 
short piles. 

(5) The embankment may be made of materials light enough 
to form a sort of raft, floating on the soft ground, such as hurdles, 
fascines, timber platforms, or dry peat. Dry peat was the material 
used by George Stephenson to carry the Liverpool and Manchester 
Railway across Chat Moss. Its heaviness, when well dried in the 
air, is about 30 pounds per cubic foot; and when saturated with 
water, 63 pounds. On the dry-peat embankment was placed a 
platform of two layers of hurdles to carry the ballast. 

(6) Should all other expedients fail, a marsh or bog may still 
be crossed by throwing in stones or gravel and sand, until an 
embankment is formed resting on the hard stratum below, and 
with its top rising to the required level. It is found that the 
material of the embankment assumes the same natural slope that 
it would do in the air. 

Mr. George W. Waite, C.E., gives the following description of a 
road constructed by him in 1868 in the village of Hyde Park (now 
in the city of Chicago): 

“ The line crossed a marsh about one mile wide which extended 
from about two miles west, easterly to Lake Michigan, and south¬ 
easterly to Calumet River, a distance of tw r o miles, and was at that 
time all covered with water from a few inches to two feet deep. 
Wild rice grew all over that portion of the marsh, about 8 feet 
high, and the stalks were from £ to i inch in diameter at the 
bottom. Through the central portion of the marsh was an open 
water-way about 10 feet wide in the channel proper, with no per¬ 
ceptible current, which widened out into small lakes every few 
hundred feet. 

“ The channel and lakes had from 3 to 4 feet of water and about 
the same depth of black slush or decayed vegetable matter. 

“ Soundings showed the turf to be about 1 foot thick, with from 
2 to 6 feet of soft black vegetable mould underneath, then a hard 
bottom of blue clay. 

"The method of construction was as follows: Beginning at the 
dry ground on the south end, an 18-foot inch board, 1 foot wide, 
♦ was placed lengthwise on the outside, 9 feet from the centre, then 



EARTH-WORK. 


351 


one in the centre, G feet in advance of the first, and then one on 
the opposite side, 6 feet in advance of the middle one. Then the 
three pieces laid lengthwise were covered with 18-foot sound boards 
1 inch thick, laid crosswise and nailed as fast as laid to keep them 
in their places. On these were placed three more, lengthwise as at 
first, one in the centre and one on each side, and these were nailed 
through into the under ones. Next all the wild rice for a space of 
about 75 feet on each side was cut down and pitched with forks 
onto the floating platform or roadbed. It made a compact cover¬ 
ing about 2 feet thick. At the end of the first 500 feet a turn¬ 
around for teams on one side was made of boards doubled, 36 feet 
square, thoroughly nailed. 

“ Then the whole 500 feet of roadbed was covered 16 feet wide 
with about 15 inches thick of stone, and on this was placed 3 
inches of crushed stone. 

“ After finishing the first 500 feet the turn-around was removed 
to the end of the second 500 feet, and so on to completion. Near 
the middle of the marsh was a lake which the line crossed, some 
200 feet wide. This was covered with a bent bridge 50 feet long, 
and the balance with floats, the same as the marsh but wider. The 
bridge was placed on the pond-lily roots that everywhere abounded 
in the bottom of all these small lakes, and left about 2 feet higher 
than needed to allow for settling, but it has not yet settled more 
than some 6 inches, although a pole can be run down between the 
network of roots and into the slush underneath about 3 feet below 
the bottom of the sills before the hard bottom is reached. 

“ The road settled on an average about 2 feet, with the excep¬ 
tion of two or three short distances where it settled 3 feet, but it 
did not break through the turf in any place. At a high stage of 
water some places for a few feet in length would be 1 foot under 

water. 

“ The road has stood over 23 years and has been considerably 
travelled, and is in good condition at the present time (1892). It 
has had but very little top-dressing during the whole time. Since 
the road was constructed the marsh has nearly all been diained 
and has mostly become solid, and the land in it, which at that time 
was not worth $25.00 per acre, has just been sold for $2500.00 per 

acre.” 

658. Embankments across Bogs.—Undrained moss consists of 



352 


HIGHWAY CONSTRUCTION. 


about 90 per cent of water and 10 per cent of vegetable matter, and 
consequently while in that condition it is quite incapable of sus¬ 
taining a roadway; but in most cases the surface of the underlying 
solid ground is above the level of the waterways of the district, 
and by gradual drainage the fluid mass may be condensed into a 
more or less solid peat. The drainage should not be effected at too- 
rapid a rate, as there is a liability of the escaping water carrying off 
with it the particles of vegetable matter, causing the sides of the 
ditches to collapse, and producing fissures on the surface of the 
moss which, becoming filled with water or ice, extend more and 
more. 

The drainage of the strip of moss along the site of the intended 
roadway should be effected by side drains, carried gradually down 
and into the solid underlying ground. And if this can be done, it 
is probable that the moss by conversion into peat will be reduced 
by about one third of its total thickness. The sides of the drains, 
instead of being sloped, should be cut in a series of steps or benches, 
each of about three feet deep and three feet broad, down to the re¬ 
quisite level, so as to expose as large a surface as possible to the 
influence of wind and sun, and thereby produce a comparatively 
hard skin of peat, and consequently lessen the destructive action 
of frost. 

The side ditches should be cut parallel to the axis of the road¬ 
way and at a distance from the centre line on each side of 30 or 
more feet, depending upon the width of the berm intended to be 
left between th eedge of the roadway and the side ditch. The berm 
should not be less than six feet. Transverse drains should be cut 
at right angles to the side drains, and at distances apart not exceed¬ 
ing 30 feet. These transverse drains should extend across and 
beyond the side drains from 50 to 100 feet. The material exca¬ 
vated from these drains should not be deposited near their edges, or 
slips will probably occur ; it may be spread on the roadway site. 

* After the draining is completed, the roadway may be formed of 
sand and surfaced with broken stone. 

659. Embankments on Hillsides.—When the axis of the road¬ 
way is laid out on the side slope of a hill, and the road is formed 
partly by excavating and partly by embanking, the usual and most 
simple method is to extend out the embankment gradually along 
the whole line of the excavation. This method is insecure; ths 



EARTH-WORK. 


353 


excavated material if simply deposited on the natural slope is liable 
to slip, and no pains should be spared to give it a secure hold, par¬ 
ticularly at the toe of the slope. The natural surface of the slope 



Fig. 61. SHOWING METHOD OF CONSTRUCTION ON 

HILLSIDES. 

should be cut into steps as shown in Figs. 61, 62. The dotted 
line AB represents the natural surface of the ground, CEB the 
excavation, and ADC the embankment, resting on steps which 
have been cut between A and C. The best position for these steps 
is perpendicular to the axis of greatest pressure. If AD is inclined 



^3 

Fig. 62. SHOWING METHOD OF CONSTRUCTION ON 

HILLSIDES. 

at the angle of repose of the material, the steps near A should be 
inclined in the opposite direction to AD, and at an angle of nearly 









354 


HIGHWAY CONSTRUCTION. 


90 degrees thereto, while the steps near C may he level. If stone is 
abundant, the toe of the slope may be further secured by a dry wall 
of stone. 

On side hills of great inclination the above method of construc¬ 
tion will not be sufficiently secure; retaining-walls of stone must 
be substituted for the side slopes of both the excavations and em¬ 
bankments. These walls may be made of stone laid dry, when 
stone can be procured in blocks of sufficient size to render this 
kind of construction of sufficient stability to resist the pressure of 
the earth. But when the blocks of stone do not offer this security, 
they must be laid in mortar. The wall which forms the slope of 
the excavation should be carried up as high as the natural surface 
of the ground. Unless the material is such that the slope may be 
safely formed into steps or benches as shown in Figs. 61 and 62, the 
wall that sustains the embankment should be built up to the surface 
of the roadway, and a parapet wall or fence raised upon it, to pro¬ 
tect pedestrians against accident. (See Figs. 56 and 63.) 

660. Roadways on Rock-slopes. —On rock-slo]3es when the 
inclination of the natural surface is not greater than one perpen¬ 
dicular to two base, the road may be constructed partly in excava¬ 
tion and partly in embankment in the usual manner or, as shown 
in Figs. 63, 64, 65, by cutting the face of the slope into horizontal 



-!G. 63. SHOWING METHOD OF CONSTRUCTION ON 

HILLSIDES. 


steps with vertical faces, and building up the embankment in the 
form of a solid stone wall in horizontal courses, either dry or laid 
in mortar. Care is required in proportioning the steps, as all attempts 










EARTH-WORK. 


355 


to lessen the quantity of excavation by increasing the number and 
diminishing the width of the steps require additional precautions 
against settlement in the built-up portion of the roadway. 



Fig. 64. SHOWING METHOD OF CONSTRUCTION ON 

HILLSIDES. 

When the rock-slope has a greater inclination than 1: % the 
whole of the roadway should be in excavation. 

In some localities roads have been constructed along the face of 
nearly perpendicular cliffs on timber frameworks consisting of hori¬ 
zontal beams, firmly fixed at one end by being let into holes drilled 
in the rock, the other end being supported by an inclined strut which 
rests against the rock in a shoulder cut to receive it. There are 
also examples of similar platforms suspended instead of being sup¬ 
ported. 

661. The vertical faces of rock-cliffs present the most formida¬ 
ble obstacles to the formation of roads. When the rock is suffi¬ 
ciently hard and not liable to early disintegration a half-tunnel like 
DEF , Fig. 66, may be formed by blasting; but if it be too soft and 
rotten to admit of this being done, the best plan, if the cliff be of 
any great height BE above the formation level, is to blow out the 
whole piece GEF by a large mine at E. Mining should not, as a 
rule, be employed where there is a chance of the strata being blown 
out downwards according to the dip, for a piece may be blown out, 
like the shaded portion Fig. 67, when much time and expense are 
entailed in rectifying the level. 

The general mode of attacking a vertical cliff and of forming a 
half-tunnel is shown in Fig. 68. The large blasts, a, a, a, a, driven 
8 feet in depth, at an angle of 45 degrees, are 7 feet 3 inches apart 
horizontally and 5 feet vertically. The small holes, b, b, etc., 3 feet 






i-rt 


356 


HIGHWAY CONSTRUCTION. 


EXAMPLES OF ROADS ON ROCK SLOPES. 































EARTH-WORK. 


Of) i 


apart and 3 feet deep, which are not fired, serve to determine and 
facilitate rupture at the proper level. These blasts, when fired, 
generally blow out or loosen a piece like ABCD. The remaining 
space, BEF\ is blown out in the same manner. 

662. Rock Excavation. —Excavation in hard rock is usually per_ 
formed by means of some explosive material inserted in a hole 
bored in the rock, and when ignited it loosens the mass and permits 
of its being broken up into pieces of the required size. 

The diameter and depth of the hole vary with the quantity of 
rock to be loosened at each blast, and also with the strength of the 
explosive used. 

The quantity of rock loosened, other conditions being the same, 
is roughly proportional to the cube of the “ line of least resistance/’ 
which is generally the shortest distance from the centre of the 
charge to the surface of the rock. 

If E — the quantity of the explosive in pounds, and 

L — the line of least resistance in feet, then 

E — CL 3 ; 

C — .032 blasting powder; 

= .005 “ cotton; 

= .003 nitroglycerine or dynamite. 

Ordinary blasting powder, 1 pound of which occupies about 30 
cubic inches, is ignited by means of a fuse, which burns at the rate 
of about 2 feet per minute, varying slightly with each coil. 

In estimating it is usual to allow f of a pound of powder to each 
cubic yard of solid rock. The actual quantity required will vary 
with the nature of the rock and its degree of compactness or loose¬ 
ness, the latter requiring most powder. 

Dynamite and nitroglycerine should be fired by percussion. 
Detonating tubes or caps are made for the purpose, which explode 
on being ignited either by an ordinary fuze or by a galvanic battery. 

663. Blasting. 

If L = least line of resistance in feet; 

X = number of ounces of powder required to blast any rock 
when L = 2 feet; 

P = quantity of powder in ounces required,—then 



358 


HIGHWAY CONSTRUCTION. 


or, when X — 4 ounces, 


P = 


XL 3 
8 ' 



L should not exceed one half the depth of hole. 


TABLE LXVII. 

Amount of Charge when X — 4 ounces. 


L 

Charge of Powder. 

L 

Charge of Powder. 

feet. 

lbs. 

oz. 

feet. 

lbs. 

oz. 

1 

0 

1 

5 

3 

141 

2 

0 

4 

6 

6 

12 

3 

0 

m 

8 

16 

0 

4 

2 

0 





In small blasts one pound of powder will loosen about 4\ tons. 
In large blasts one pound of powder will loosen about 2f tons. 
Thirty cubic inches of powder weigh one pound. Hence we 
have the following table, showing the capacity of drill-holes: 


TABLE LXVIII. 
Capacity of Drill-holes. 


Diameter 
of Hole in 
inches. 

Area in square 
inches. 

Ounces of 
Powder in one 
inch deep. 

Powder in one 
foot deep. 

Depth of hole in 
inches to contain 
one lb. of Pow r der. 

1 

0.7854 

0.419 

lbs. oz. 

0 5.028 

38.197 

H 

1.7671 

0.942 

0 11.300 

16.976 

2 

3.1416 

1.676 

1 4.112 

9.549 

2£ 

4.9087 

2.618 

1 15.416 

6.112 

3 

7.0686 

3.770 

2 13.240 

4.244 


664. In blasting no loud report should be heard nor stones be 
thrown out. The best effect is produced when the report is trifling, 
and when the mass is lifted and thoroughly fractured without the 
projection of fragments. If the rock be only shaken by a blast 
and not moved outward, a second charge in the same hole will be 
very effective. 

























EARTH-WORK, 


359 


Any kind of compact brush, such as pine or cedar boughs, laid 
on rocks about to be blasted, will almost completely prevent the 
flying of fragments, and thus lessen the danger to persons and 
buildings in the vicinity. 

So much, however, depends upon the character of the rock to be 
excavated, whether it is hard or soft, stratified or unstratified, and 
whether the position of the excavation allows of arranging the drill¬ 
holes in the most advantageous manner, that the above figures must 
be regarded as only approximately correct. 

665. Holes for blasting rock are bored either by hand or machine 
drills. Shallow cuts, loose boulders, etc., are more cheaply bored by 
hand, but deep and extensive cuttings are more economically car¬ 
ried out by the use of machine drills operated either by steam or 
compressed air. 

666. Hand-drilling. —The speed with which holes may be bored 
in rock varies of course with the hardness of the rock and the 
diameter of the hole. The smaller the diameter of the hole the 
greater the depth that can be bored in a given time; and the depth 
will be greater in proportion than the decrease of the diameter. 

The average rate of progress made by a good drillman working 
a churn-drill in granite and the harder rocks is about as follows : 

Diam. of Drill. Depth bored per hour. 

Inches. Inches. 

3.4 

2 *. 5 

2 *. 6 

2 . 8 

If.10 

When the hole exceeds four feet in depth two men are required 
to operate the drill. 

667. Machine-drilling. —Machine drills bore holes from J to 6 
inches in diameter. The rate of progress is controlled by the same 
(conditions as hand-drilling, and ranges from three to ten feet per 
'.hour, depending on the character of the rock and the size of the 
'machine. 

668. Cost of Rock Excavation.— The cost of simply excavating 
rock is from four to six times that of earth, and is largely con¬ 
trolled by the skill of the overseer, especially as regards carrying the 
excavation to its full depth. If this is not done, the amount left in 








360 


HIGHWAY COYSTKUCTIOH. 


the bottom, especially if it is of little depth, will cost several times 
more per yard to remove it than the cost per yard of the main cut. 

669. Earth Excavation—Loosening the Earth. —The loosening 
of the material in shallow cuttings and in light soils is done best 
by the plough, and its removal is economically executed with drag or 
wheeled scrapers. Gravel, clay, and hardpan require to be loosened 
by the pick, or if the depth be great, explosives may be employed. 

670. Transport of Earth. —The transport of earth is effected in 
the following ways : 

(«) Throiving with a Shovel, when the distance horizontally 
does not exceed 12 feet nor vertically 6 feet. 

(b) Wheelbarrows may be employed running upon a plank for 
distances up to 200 feet. 

(c) Carts. —Between 200 and 500 feet two-wheeled dump-carts 
may be used. 

(i d) Scrapers .—The economical limit for drag-scrapers is about 
150 feet. Wheeled scrapers may be employed up to 500 feet. 

( e ) For hauls over 500 feet, where a large amount of work is to 
be done, a track with dump-cars drawn by horses will be found 
jirofitable. 

(/) Dump-wagons. —The dump-wagon is a recent invention; it 
consists of a four-wheeled wagon, the body of which turns on a 
horizontal axle, so that it can be tipped over by a single movement 
of a lever and the earth dumped out. Their capacity varies from 35 
to 45 cubic feet. They may be economically employed in long 
hauls. 

The distance, however, depends much upon the difficulty of 
getting out the earth. With hard clay, requiring two picks to a 
shovel, and with a small surface to work upon, two carts upon 
an ordinary road will take away all that a dozen men can get out; 
while with an easy soil, where one pick will keep half a dozen 
shovels busy, a larger number of vehicles will be required, or a 
quicker haul, which may be obtained by putting down a track. 
The less the haul, or the greater the speed of transport, the 
fewer may be the number of vehicles to remove a given amount 
of material. The chief point to be gained is to arrange the different 
classes of laborers so that none shall be kept waiting. Everything 
depends upon the tact for management possessed by the overseer. 

671. Loosening and Transporting by Machinery.— A machine 



EARTH-WORK. 


361 


called the New Era Grader (Fig. 211) (Chap. XXIII) has been 
developed for both loosening the earth and automatically transport¬ 
ing and depositing it in the bank when the material is obtained 
from side ditches, as in the case of building a bank across a plain. 

The machine consists of a plough which loosens and raises the 
earth, depositing it upon a transverse carrying-belt, which conveys 
it from the excavation to the bank. The carrier-belt is of heavy 
three-ply rubber 3 feet wide, and can be adjusted to deliver the 
earth at 14, 17, 19, or 22 feet from the plough. 

The machine will work in any material that can be loosened 
with a plough. The motive power is horses, usually twelve in 
number. 

The capacity of the machine varies from 100 to 150 cubic yards 
per hour, depending upon the resistance of the material to be 
moved. 

The number of attendants required to operate the machine is 
three. The cost per cubic yard loosened and placed in bank will 
depend upon wages and team-hire. With wages at 20 cents per 
hour for laborers, and horsehire at 10 cents each per hour, the cost 
per cubic yard would be 1.80 cents. 

The machine can also be used to excavate material in deep cuts. 
When so employed, dump-wagons are used to transport the earth. 
The carrier of the machine is set to deliver at 10 feet ; the wagons 
are driven under it and automatically loaded with from 1J to 1^- 
yards of earth in from 20 to 30 seconds. The machine can thus 
load from 60 to 80 wagons per hour. 

672. Cost of Earth- work.—Regarding the cost of executing 
earthwork, no fixed rules can be given; it depends largely upon the 
location, kind and cost of labor, and character of the management. 
In general it ranges from 10 to 35 cents per cubic yard. 

The several items that go to make up the total cost of earth¬ 
work are the loosening of the earth, either by ploughs, picks, or 
explosives, the loading it into the barrows, carts, or other vehicles, 
the moving and emptying it, the spreading it out upon the em¬ 
bankment, the return of the vehicle, the keeping of the road in 
order, the wear and tear of tools and vehicles, the interest on the 
cost of the equipment, the wages of the overseers, and the contract/ 
or’s profit. 

673. Haul. —The cost of removing excavated material when the 




3G2 


HIGHWAY CONSTRUCTION. 


distance does not exceed a certain specified limit is included in the 
price per cubic yard of the material as measured in the cutting. 
But when the material must be carried beyond this limit, the extra 
distance is paid for at a stipulated price per cubic yard per 100 
feet. The extra distance is known by the name of “ haul,” and is 
to be computed by the engineer with respect to so much of the 
material as is affected by it. 

The contractor is entitled to the benefit of all short hauls (less 
than the specified limit), and material, so moved should not be aver¬ 
aged against that which is carried beyond the limit. Therefore, in 
all cuts the material of which is all deposited within the limiting 
distance, no calculation of haul is to be made. 

The contractor must haul free that portion of the cutting no 
one yard of which is carried beyond the specified limit. There¬ 
fore this portion is first to be determined in respect to its extent, 
and the number of cubic yards contained in it is to be deducted 
from the total content of the cutting, before estimating the haul 
upon the remainder. Find on the profile of the line two points, 
one in excavation and the other in embankment, such that while 
the distance between them equals the specified limit, the included 
quantities (allowing for shrinkage) of excavation and embankment 
shall just balance. These points are easily found by trial with the 
aid of the cross-sections and calculated quantities, and become the 
starting points from which the haul of the remainder of the 
material is to be estimated. 



Fig. 69. ILLUSTRATING CALCULATION OF OVERHAUL. 

Fig. 69 represents a cut and fill in profile. The distance AB is. 
the limit of free haul. The materials taken from AO just make 
the fill OB and without charge for haul; but the haul for every 
cubic yard taken from AC and carried to the fill BD is subject 











EARTH-WORK. 


363 


to charge for the distance it is carried, less AB. It would be 
impossible to find the distance that each separate yard is carried, 
but we know from mechanics that the average distance for the 
entire number of yards is the distance between the centres of 
gravity of the cut AC, and of the fill BD, which is made from it. 
If, therefore, X and Y represent the centres of gravity, the actual 
average haul is the sum of the distances (AX-j- BY), and this 
(expressed in feet) multiplied by the number of cubic yards in the 
cut AC gives the product to which the- price for haul applies. 

If a cut is divided and parts are carried in opposite directions,, 
the calculation of each part terminates at the dividing line. If a 
portion of the material in AC is wasted, it must be deducted and 
the haul calculated on the remainder. 

The specified limit is sometimes made as low as 100 feet, some¬ 
times as high as 1000 feet. A limit of about 300 feet, however, is 
usually most convenient, as it includes the wheelbarrow work and 
a large part of the carting, while it protects the contractor on such 
long hauls as may occur. 

674. Calculating the Amount of Earth-work.—The quantity of 
excavation and embankment expressed in cubic yards is required 
to be known, in order to compare the amount of work to be done 
upon the different trial lines which may have been surveyed. For 
this purpose the method of averagingend areas is sufficiently exact; 
or if expedition is desired, the quantities may be taken from any of 
the many tables of quantities which for level cross-section are 
reliable. For other than level cross-section the tables will he in 
error, even with the use of the auxiliary formula given with them 
for the purpose of ascertaining the extra amounts to he added for 
irregular sections. The error in the quantities obtained by using 
the tables for irregular sections will he of no practical moment; in 
fact, it will he more an advantage by allowing a leeway of about 
3 or 4 per cent in excess. 

675. After final location a more accurate calculation is required, 
for the reason that the contractors who usually perform the work 
are paid, not by the day, nor in the lump, but at a certain price 
per cubic yard, the exact determination of which is therefore 
required to ascertain their just dues. For this purpose the pris- 
moidal formula is the only one to use. It is as follows: To the sum 



364 


HIGHWAY CONSTRUCTION". 


of the end areas add four times the middle area. Multiply the 
sum by one sixth of the length. Divide the product by 27. 

676. Calculation of Half-widths and Areas.—The boundaries of 
a piece of earth-work in general are as follows: 

(1) The base, or subgrade surface, which forms the bottom of a 
cutting or the top of an embankment. 

(2) The original surface of the ground, which forms the top of 
a cutting and the bottom of an embankment. 

(3) The sides, or slopes, which connect the base with the 
natural surface, and whose inclination is the steepest consistent 
with the permanent stability of the material. 

677. Examples of Cross-sections.—Figs. 70 to 76 represent 
examples of cross-sections of pieces of earth-work, in each of which 
DE is the base, AB the natural surface, and DA and EB are the 
slopes. In Fig. 70 the natural surface is horizontal; in Figs. 73, 74, 
75, 76 it slopes sideways, being what is termed “ side-long ground.” 
Figs. 71, 72 represent forms that occasionally occur. Figs. 70 to 76 
represent cuttings; to represent embankments it is only necessary 
to conceive them to be turned upside down. Figs. 75, 76 represent 
pieces of earth-work, of which one side, CEB , is in cutting called 
“side cutting” and the other, CD A, in embankment. 

The half-width of a piece of earth-work is the horizontal dis¬ 
tance measured at right angles from a given point in the centre¬ 
line of the base to one edge of the cutting or embankment; and 
although it is called “ half-width,” it is very generally different at 
opposite sides of that centre line. 

Each half-width consists of two parts: the real half-width of 
the base, which is fixed by the design of the work, and the 
horizontal breadth of one slope, which is to be found by calculation 
or by drawing. 

In each of the figures 70 to 76, C represents a point in the 
centre-line, as marked on the ground; F, the point vertically above 
or below it in the centre-line of the base; DG and EH are vertical 
lines through the edges of the base; DF and FE are the half- 
widths of the base. 

In Fig. 70, where the ground is level across, GA and HB are 
the widths of the slope, and CA and CB the half-v/idths of the 
-earth-work. 

In Figs. 74, < 5, and < 6, where the ground slopes sideways, the 



EARTH-WORK. 


365 


EXAMPLES OF EARTH-WORK CROSS-SECTIONS. 



■42 























366 


HIGHWAY CONSTRUCTION". 


vertical lines through D, F, and E are produced, if necessary, 
and are cut at right angles by horizontal lines, ALM and BNP, 
drawn through the edges of the earth-work. AL and BN are 
the widths of the slopes; and MA and PB are the half-widths 
of the earth-work. 

When the natural surface of the ground is rugged, the best 
method of determining the widths of the slopes is by measure¬ 
ment upon a series of cross-sections of the proposed work 
plotted to the same scale horizontally and vertically. 

678. Calculation of Sectional Areas of Earth-work.—The com¬ 
putation of the areas of a series of cross-sections of a piece of 
earth-work is necessary to ascertain its volume or cubical quan¬ 
tity. If the ground is rugged, it may be necessary to find the 
area of each cross-section by measurements made upon a drawing; 
but if the ground is nearly or exactly level across, or has nearly or 
exactly a uniform sidelong slope, the area of a given cross-section 
can be computed from the same data which serve to compute the 
width of the slopes. 

679. Formulas for the Calculation of Areas. 

CF 

Fig. 70. Area = . (AB + BE). 


Figs. 71, 72,73. Area = AB. +~ .(GD + HE). 

Fig. 74. Area = J(cotan X - cotan V f - DE\K. 

(For values of K see Table LXIX.) 

Fig. 75. Area of the larger triangle = — Ip -' 

£ 

Fig. 75c Area of the smaller triangle = — OF).DG* 

2 


Fig. 76. In this figure C and F coincide, that is, there is neither 
cut nor fill, the triangles are similar, and the area is expressed by 
the same formula given for Fig. 75. 








EARTH-WORK. 


36? 


The letters on Figs. 70 to 76 denote: 

L = angle of side slopes with horizon. 

X — angle of natural surface with horizon. 
S = ratio of slopes, usually 14 : 1. 

A G or HB ABDE 


S = cot L = 


CF 


2CF 


AG and HB = CF . S = CF . cot L. 
AB = 2CF . S+DE. 


TABLE LXIX. 

Values of K for Different Slopes. (G. L. Molesworth.) 


Angle of 

Values of K. 

Gi'ound. 






X. 

i to 1. 

£ to 1. 

*tol. 

1 to 1. 

H to 1. 

10° 

.0922 

.0967 

.1016 

.107 

.1199 

12 

.1123 

.119 

.1265 

.1351 

.1562 

14 

.1329 

.1424 

.1533 

.1661 

.1992 

16 

.1543 

.1672 

.1794 

.2008 

.2512 

18 

.1766 

.1937 

.2145 

.2407 

.3164 

20 

.2 

.2222 

.25 

.2857 

.4009 

22 

.2252 

.2538 

.2907 

.3389 

.5128 

24 

.25 

.2857 

.3342 

.4012 

.6702 

26 

.2777 

.3225 

.3846 

.4761 

.909 

28 

.3067 

.362 

.4421 

.5675 

1.3123 

30 

.3373 

.4058 

.5091 

.6830 

2.1551 

32 

.3703 

.4545 

.5882 

.8333 


34 

.4058 

.5091 

.6830 

1.0373 


36 

.444 

.5707 

.7987 

1.3297 


38 

.4854 

.641 

.9434 

1.7857 


40 

.5307 

.7225 

1.131 

2.6041 


42 

.5807 

.8183 

1.385 



44 

.6364 

.9345 

1.754 



46 

.6983 

1.0729 

2.315 



48 

.7692 

1.25 




50 

.8488 

1.475 





Fig. 77 shows a profile and cross-sections of a piece of earth¬ 
work. 

The letters denote: 

0 = a zero point, or the point at which a cutting ends and ad 
embankment begins. 

L — the distance between two parallel cross-sections. 

I — the distance from a cross-section to the zero point. 




























368 


HIGHWAY COKSTKUCTIOX 




LU 


O- 



CO 


O/ 


_ Ll . 


O h 


- U __ 
























EARTH-WORK 


3G9 


TABLE L X X. 

(EARTH- WORK.) 

Contents of 1-foot Length in Cubic Feet. 


(For lengths of 100 feet move decimal two places.) 


Height. Ft. 1 

Central Portion. 

Base in feet. 

Contents of Both Slopes. 

Height. Ft. ! 

20 

30 

33 

40 

50 

60 

66 

i : 1 

i : 1 

1 : 1 

1 : 1 

H : 1 

2:1 

3 : 1 

1 

20 

30 

33 

J 

40 

50 

60 

66 

.25 

.5 

.75 

1 

1.5 

2 

3 

1 

2 

40 

60 

66 

80 

100 

120 

132 

1 

2 

3 

4 

6 

8 

12 

2 

3 

60 

90 

99 

120 

150 

180 

198 

2.25 

4.5 

6.75 

9 

13.5 

18 

27 

3 

4 

80 

120 

132 

160 

200 

240 

264 

4 

8 

12 

16 

24 

32 

48 

4 

5 

100 

150 

165 

200 

250 

300 

330 

6.25 

12.5 

18.75 

25 

37.5 

50 

75 

5 

6 

120 

180 

198 

240 

300 

360 

396 

9 

18 

27 

36 

54 

72 

108 

6 

7 

140 

210 

231 

280 

350 

420 

462 

12.25 

24.5 

36.75 

49 

73.5 

98 

147 

r* 

i 

8 

160 

240 

264 

320 

400 

480 

528 

16 

32 

48 

64 

96 

128 

192 

8 

9 

180 

270 

297 

360 

450 

540 

594 

20.25 

40.5 

60.75 

81 

121.5 

162 

243 

9 

10 

200 

300 

330 

400 

500 

600 

660 

25 

50 

75 

100 

150 

200 

300 

10 

11 

220 

330 

363 

440 

550 

660 

726 

30.25 

60.5 

90.75 

121 

181.5 

242 

363 

11 

12 

240 

360 

396 

480 

600 

720 

792 

36 

72 

108 

144 

216 

288 

432 

12 

13 

260 

390 

429 

520 

650 

180 

858 

42.25 

84.5 

126.75 

169 

253.5 

338 

507 

13 

14 

280 

420 

462 

560 

700 

840 

924 

49 

98 

147 

196 

294 

392 

588 

14 

15 

300 

450 

495 

600 

750 

900 

990 

56.25 

112.5 

168.75 

225 

337.5 

450 

675 

15 

10 

320 

480 

528 

640 

80.1 

960 

1056 

64 

128 

192 

256 

384 

512 

768 

16 

17 

340 

510 

561 

680 

850 

1020 

1122 

72.25 

144.5 

216.75 

289 

433.5 

578 

867 

17 

18 

360 

540 

594 

720 900 

1080 

1188 

81 

162 

243 

324 

486 

648 

972 

18 

19 

380 

570 

627 

760 

950 

1140 

1254 

90.25 

180.5 

270.75 

361 

541.5 

722 

1083 

19 

20 

400 

600 

660 

800 

1000 

1200 

1320 

100 

200 

300 

400 

600 

800 

1200 

20 

21 

420 

630 

693 

840 

1050 

1260 

1386 

110.25 

220.5 

330.75 

441 

661.5 

882 

1323 

21 

22 

440 

660 

726 

880 

1100 

1320 

1452 

121 

242 

363 

484 

726 

968 

1452 

22 

23 

460 

690 

759 

920 

1150 

1380 

1518 

132.25 

264.5 

396.75 

529 

793.5 

1058 

1587 

23 

24 

480 

720 

792 

960 

1200 

1440 

1584 

144 

288 

432 

576 

864 

1152 

1728 

24 

25 

500 

750 

825 

1000 

1250 

1500 

1650 

156.25 

312.5 

468.75 

625 

937.5 

1250 

1815 

25 

26 

520 

780 

858 

1040 

1300 

1560 

1716 

169 

338 

507 

676 

1014 

1352 

2028 

26 

27 

540 

810 

891 

1080 

1350 

1620 

1782 

182.25 

364.5 

546.75 

729 

1093.5 

1458 

2187 

27 

28 

560 

8-10 

924 

1120 

1400 

1680 

1848 

196 

392 

588 

784 

1176 

1568 

2352 

28 

29 

580 

870 

957 

1160 

1450 

1740 

1914 

210.25 

420.5 

630.75 

841 

1261.5 

1682 

2523 

29 

30 

600 

900 

990 

1200 

1500 

1800 

1980 

225 

450 

675 

900 

1350 

1800 

2700 

30 

31 

620 

930 

1023 

1240 

1550 

1860 

2046 

240.25 

480.5 

720.75 

961 

1441.5 

1922 

2883 

31 

32 

640 

960 

1056 

1280 

1600 

1920 

2112 

256 

512 

768 

1024 

1536 

2048 

3072 

32 

33 

660 

990 

1089 

1320 

1650 

1980 

2178 

272.25 

544.5 

816.75 

1089 

1633.5 

2178 

3267 

33 

34 

680 

1020 

1122 

1360 

1700 

2040 

2244 

289 

578 

867 

1156 

1734 

2312 

3468 

34 

35 

700 

1050 

1155 

1400 

1750 

2100 

2310 

306.25 

612.5 

918.75 

1225 

1837.5 

2450 

3675 

35 

36 

720 

1080 

1188 

1440 

1800 

2160 

2376 

324 

648 

972 

1296 

1944 

2592 

3888 

36 

37 

740 

1110 

1221 

1480 

1850 

2220 

2442 

342.25 

684.5 

1026.75 

1369 

2053.5 

2738 

4107 

37 

38 

760 

1140 

1254 

1520 

1900 

2280 

2508 

361 

722 

1083 

1444 

2166 

2888 

4332 

38 

39 

780 

1170 

1287 

1560 

1950 

2340 

2574 

380.25 

760.5 

1140.75 

1521 

2281.5 

3042 

4563 

39 

40 

800 

1200 

1320 

1600 

2000 

2400 

2649 

400 

800 

1200 

1600 

2400 

3200 

4800 

40 

41 

820 

1230 

1353 

1640 

2050 

2460 

2706 

420.25 

840.5 

1260.75 

1681 

2521.5 

3362 

5043 

41 

42 

840 

1260 

1386 

1680 

2100 2520 

2772 

441 

882 

1323 

1764 

2646 

3528 

5292 

42 

43 

860 

1290 

1419 

1720 

2150 

2580 

2838 

462.25 

924.5 

1386.75 

1849 

2773.5 

3698 

5547 

43 

44 

880 

1320 1 

1452 

1760 

2300 

2640 

2904 

484 

968 

1452 

1936 

2904 

3872 

5808 

44 

45 

900 

1350i 

1485 

1800 

2250 

2700 

2970 

506.25 

1012.5 

1518.75 

2025 

3037.5 

4050 

6075 

45 

46 

920 

138o! 

1518 

1840 

2300 

2760 

3036 

529 

1058 

1587 

2116 

3174 

4232 

6348 

46 

47 

940 

1410 

1551 

1880 

2350 

2820 

3102 

552.25 

1104.5 

1656.75 

2209 

3313.5 

4418 

6627 

47 

48 

960 

14401 

1584 

1920 

2400 

2880 

3168 

576 

1152 

1728 

2304 

3456 

4608, 

6912 

48 

49 

980 

1470 

1617 

1960 

2450 

2940 

3234 

600.25 

1200.5 

1800.75 

2401 

3601.5 

4802 

7203 

49 

50 

1000 

1500 j 

1650 

2000 

2500 

3000 

3300 

625 

1250 

1875 

2500 

3750 

5000 

1500 

50 







































































370 


111GHWAY CONSTRUCTION". 


The cubical contents between sections 5 and 6 and between 
sections 7 and 8 may be ascertained by the prismoidal formula; the 
contents between the zero point and the continuous cross-sections 
by the following formula: 


Cubic contents in feet = l . CF 


/CF.S 
V 3 



r 

680. Zero Point.—The zero point should be found on the 
ground. If this has not been done, it may be ascertained as follows: 
Take the cut and the fill at the stations between which it lies; then, 
the sum of the cut and the fill : the cut :: the distance from the 
cut to the fill : the distance from the cut to the zero point. 

681. Earth-work Table.—Table LXX contains the contents in 
cubic feet for each foot in length of the central portion and side 
slopes of embankments or cuttings. To use table, note the con¬ 
tents for the central portion due to the required base and depth, 
add contents given for the required slope and depth, and multiply 
by the length; the product divided by 27 gives cubic yards. 







CHAPTER XIV. 


DRAINAGE—CULVERTS. 

682. Drainage.—The drainage of roadways is of two kinds, viz., 
surface and subsurface. The first provides for the speedy removal 
of all water falling on the surface of the pavement; the second 
provides for the removal of the underground water found in the 
body of the road, a thorough removal of which is of the utmost 
importance and essential to the life of the road-covering. A road¬ 
covering placed on a wet undrained bottom will be destroyed by 
both water and frost, and will always be troublesome and expen¬ 
sive to maintain; perfect subsoil drainage is a necessity and will 
be found economical in the end even if it requires considerable 
expense to secure it. 

683. The methods employed for securing the subsoil drainage 
must be varied according to the character of the natural soil, each 
kind of soil requiring different treatment. 

684. The natural soils may be divided into the following 
classes: silicious, argillaceous, and calcareous; rock, swamps, and 
morasses. 

685. The silicious and calcareous soils, the sandy loams and 
rock present no great difficulty in securing a dry and solid founda¬ 
tion. Ordinarily they are not retentive of water and therefore 
require no underdrains; ditches on each side of the road will gener¬ 
ally be found sufficient. 

686. The argillaceous soils and softer marls require more care; 
they retain water and are difficult to compact, except at the 
surface; and they are very unstable under the action of water and 
frost. 

The drainage of these soils may be effected by transverse drains 
and deep side ditches of ample width. The transverse drains are 
placed across the road, not at right angles but in the form of an in- 

371 


372 


HIGHWAY CONSTRUCTION. 


verted V (y\), with the point directed up-hill; the depth at the angle- 
point should not be less than 18 inches below the subgrade surface* 
and each branch should descend from the apex to the side ditches 
with a fall of not less than 1 inch in 5 feet. The distance apart of 
these drains will depend upon the wetness of the soil; in the case 
of very wet soil they should be at intervals of 15 feet, which may 
be increased to 25 feet as the ground becomes drier and firmer. 

687. The transverse drains are best formed of unglazed circular 
tile of a diameter not less than 3 inches, jointed with loose collars. 
The tiles are made from terra-cotta or burnt clay, are porous, 
and far superior to all other kinds of drains. They carry olf the 
water with greater ease, rarely if ever get choked up, and only 
require a slight inclination to keep the water moving through 
them. 

The tiles are made in a variety of forms, as horseshoe sole, 
double sole, and round, the name being derived from the shape of 
their cross-sections. Round tile is superior to all other forms. 
The inside diameter of these tiles varies from 1^ to 6 inches, but 
they are manufactured as large as 24 inches. Pieces of the larger 
pipe serve as collars for the smaller sizes. They are made in 
lengths of 12, 14, and 24 inches, and in thickness of shell from J 
of an inch to 1 inch. 

The collar which encircles the joint of the small tile allows a 
large opening, and at the same time prevents sand and silt from 
entering the drain. Perishable material should not be used for 
jointing. When laid in the ditch they should be held in place by 
small stones. Connections should be made by proper Y-branches. 

The outlets may be formed by building a dwarf wall of brick 
or stone, whichever is the cheapest or most convenient in the 
locality. The outlet should be covered with an iron grating to 
prevent vermin entering the drain-pipes, building nests and thus 
choking up the water-way, (See Fig. 82.) 

Silt-basins should be constructed at all junctions and wherever 
else they may be considered necessary; they may be made from 
a single 6-inch pipe (Fig. 83), or constructed of brick masonry as 
shown in Fig. 84. 

The trenches for the tiles should be excavated at least 3 feet 
wide on top and 12 inches on the bottom. After the tiles are laid 
the trenches must be tilled to subgrade level with round field or 




DRAINAGE—CULVERTS. 


373 


cobble stones; stones with angular edges are unsuitable for this 
purpose. Fine gravel, sand, or soil should not be placed over the 
drains. Bricks and flat stones may be substituted for the tiles, and 
the trenches filled as above stated. 

Figs. 78 to 81 show different forms of underdrains. 

688. Cost of Drains per Foot.—The cost (including labor and 
materials) of different drains may be taken as follows: 

2- inch round tile.$0.19 to $0.28 per foot 

3- “ “ “ . 0.22 “ 0.35 “ “ 

4- “ “ “ . 0.25 “ 0 40 “ “ 

Triangular brick. 0.22 “ 0.35 “ “ 

Brick, 4 inches by 4 inches. 0.40 “ 0.95 “ “ 

Stone... 0.35 “ 0.50 “ 

Drainage with tiles will cost less than with any other material 
and will be more satisfactory in the end. 

689. As tile-drains are more liable to injury from frost than 
those of either brick or stone, their ends at the side ditches should 
not in very cold climates be exposed directly to the weather, but 
may terminate in blind drains, or a few lengths of vitrified clay- 
pipe reaching under the road a distance of about 3 to 4 feet from 
the inner slope of the ditch. 

690. Another method of draining the road-bed offering security 
from frost is by one or more rows of longitudinal drains. These 
drains are placed at equal distances from the side ditches and from 
each other, and discharge into cross-drains placed f rom 250 to 300 
feet apart, more or less, depending on the contour of the ground. 
The cross-drains into which they discharge should be of ample 
dimensions. On these longitudinal lines of tiles the introduction 
of catch-basins at intervals of 50 feet will facilitate the removal of 
the water. These catch basins may be excavated 3 or more feet 
square and as deep as the tiles are laid. After the tiles are laid 
the pit is filled with gravel and small stones. 

691. Fall of Drains.—It is a mistake to give too much fall to 
small drains, the only effect of which is to produce such a current 
through them as will wash away or undermine the ground around 
them, and ultimately cause their own destruction. When a drain 
is once closed by any obstruction no amount of fall which could be 
given it will again clear the passage. A drain with a considerable 
current through it is much more likely to be stopped from foreign 













374 


HIGHWAY CONSTRUCTION". 


TYPES OF DRAINS. 



Fig. 78.—Blind Drain. 



Fig. 79.—Pole Drain. 



Fig. 80—Stone Drain* 




Fig. 81 .—Tile Drain. 





































































































DRAINAGE—CULVERTS. 


375 


matter carried into it, which a less rapid stream could not have 
transported. 

A fall of 1 inch in 5 feet will generally be sufficient, and 1 inch 
in 30 inches should never be exceeded. 

692. Side Ditches.—The side ditches should be sunk 2 or 3 feet 
below the surface of the road. They should have sufficient capac¬ 
ity and declivity to receive and freely conduct away all the water 
that may find its way into them. 

These ditches may be placed either on the road or land side of 
the fence. In localities where open ditches are undesirable they 
may be constructed as shown in Figs. 87 to 89, and may be formed 
of stone or tile pipe, according to the availability of either material. 
If for any reason two cannot be built, build one; it is better than 
none. 

Springs found in the road-bed should be tapped and led into 
the side ditches. 

693. Drainage of the Surface.—The drainage of the roadway 
surface depends upon the preservation of the cross-section, with 
regular and uninterrupted fall to the sides, without hollows or ruts 
in which water can lie, and also upon the longitudinal fall of the 
road. If this is not sufficient the road becomes flooded during 
heavy rain-storms and melting snow, and is considerably damaged. 

The removal of the surface-water from country roads may be 
effected by the side ditches, into which, when there are no sidewalks, 
the water flows directly. When there are sidewalks, gutters are 
formed between the roadway and footpath, as shown in Figs. 85 to 
90, and the water is conducted from these gutters into the side 
ditches by tile-pipes laid under the walk at intervals of about 50 
feet. The entrance to these pipes should be protected against 
washing by a rough stone paving. In the case of covered ditches 
under the footpath, the water must be led into them by first passing 
through a catch-basin. These are small masonry vaults covered 
with iron gratings to prevent the ingress of stones, leaves, etc. 
Connection from the catch-basin to the ditch is made by a tile-pipe 
about 6 inches in diameter. The month of this pipe is placed a 
few feet above the bottom of the catch-basin, and the space below it 
acts as a depository for the silt carried by the water, and is cleaned 
out periodically. The catch-basins may be placed from 200 to 300 
feet apart. They should be made of dimensions sufficient to con- 



37G 


HIGHWAY CONSTRUCTOR. 


CROSS-SECTIONS OF ROADS, SHOWING METHODS OF DRAINING 
AND DIVISION INTO WHEELWAY, WALKS. ETC. 








Fig.86. 



Fig.89. 



























DRAINAGE—CULVERTS. 


377 


vey the amount of water which is liable to flow into them during 
heavy and continuous rain. 

694. If on inclines the velocity of the water is greater than the 
nature of the soil will withstand, the gutters should be roughly 
paved. In all cases the slope adjoining the foot-path should be 
covered with sod. 

A velocity of 30 feet a minute will not disturb clay with sand 
and stone. 40 feet per minute will move coarse sand. 60 feet a 
minute will move gravel. 120 feet a minute will move round pebbles 
1 inch in diameter, and 180 feet a minute will move angular stones 
If inches in diameter. 

The scour in the gutters on inclines may be prevented by small 
weirs of stones or fascines constructed by the roadmen at a nominal 
cost. At junctions and cross-roads the gutters and side ditches 
recpiire careful arrangement so that the water from one road may 
not be thrown upon another; cross-drains and culverts will be re¬ 
quired at such places. 

695. Water-breaks to turn the surface-drainage into the side 


ditches should not be constructed on improved roads. They in¬ 
crease the grade and are an impediment to convenient and easy 
travel. Where it is necessary that water should cross the road 
a culvert should be built. 

696. On side hill or mountain roads catch-water ditches should 
be cut on the mountain side above the road, to cut off and convey 
the drainage of the ground above them to the neighboring ravines. 
The size of these ditches will be determined by the amount of 
rainfall, extent of drainage from the mountain which they inter¬ 
cept, and by the distances of the ravine water-courses on each side. 

The inner road-gutter should be of ample dimensions to carry 
oif the water reaching it; when in soil it should be roughly paved 
with stone. Where paving is not absolutely necessary, but it is 
desirable to arrest the scouring action of running water during 
heavy rains, stone weirs may be erected across the gutter at conveni¬ 
ent intervals. The outer gutter need not be more than 12 inches 
wide and 9 inches deep. The gutter is formed by a depression in 
the surface of the road close to the parapet or revetted earthen 
protection-mound. The drainage which falls into this gutter is to 
be led off through the parapet, or other road-side protection at fre¬ 
quent intervals. The guard-stones on the outer side of the road 





378 


HIGHWAY CONSTRUCTION. 


are to be placed in and across this glitter, just below the drainage- 
holes, so as to turn the current of the drainage into these holes or 
channels. On straight reaches with parapet protection, drainage- 
holes with guard-stones should be placed every 20 feet apart. 
Where earthen mounds are used and it may not be convenient 
to have the drainage-holes or channels every 20 feet, the guard- 
stones are to be placed in advance of the gutter to allow the drain¬ 
age to pass behind them. This drainage is either to be run off at 
the cross-drainage of the road, or to be turned off as before by a 
guard-stone set across the gutter. 

At re-entering turns, where the outer side of the road requires 
particular protection, guard-stones should be placed every 4 feet. 
As all re-entering turns should be protected by parapets, the 
drainage-holes through them may be formed as close together as 
desired. 

697. Culverts. —Culverts are necessary for carrying under a 
road the streams it crosses, and also for conveying the surface- 
water collected in the side ditches from the upper side to that side 
on which the natural water-courses lie. 

698. Especial care is required to provide an ample way for the 
water to be passed. If the culvert is too small, it is liable to cause 
a washout, entailing interruption of traffic and cost of repairs, and 
possibly may cause accidents that will require the payment of large 
sums for damages. On the other hand, if the culvert is made un¬ 
necessarily large, the cost of construction is needlessly increased. 
Any one can make a culvert large enough; but it is the province of 
the engineer to design one of sufficient but not extravagant size. 

699. The area of water-way required depends (1) upon the 
rate of rainfall; (2) the kind and condition of the soil; (3) the 
character and inclination of the surface; (4) the condition and in¬ 
clination of the bed of the stream; (5) the shape of the area to be 
drained, and the position of the branches of the stream; (6) the 
form of the mouth and the inclination of the bed of the culvert; 
and (7) whether it is permissible to back the water up above the 
culvert, thereby causing it to discharge under a head. 

(1) It is the maximum rate of rainfall during the severest 
storms which is required in this connection. This certainly varies 
greatly in different notions, but there are almost no data to show 
what it is for any particular locality, since records generally give 




DRAINAGE—CULVERTS, 


379 


CROSS SECTIONS OF ROADS, ILLUSTRATING DRAINAGE ETC.* 




0 


Fig. 92 .— SUBURBAN STREET 


















































380 


HIGHWAY CONSTRUCTION. 


the amount per clay and rarely per hour, while the duration of the 
storm is seldom recorded. Further, probably the longer the series 
of observations the larger will be the maximum rate recorded, 
since the heavier the storm the less frequent its occurrence; and 
hence a record for a short period, however complete, is of but little 
value in this connection. Further, the severest rainfalls are of 
comparatively limited extent, and hence the smaller the area the 
larger the possible maximum precipitation. Finally, the effect of 
the rainfall melting snow would have to be considered in deter¬ 
mining the maximum amount of water for a given area. 

The maximum rainfall as shown by statistics is about one inch 
per hour (except during heavy storms), equal to 3630 cubic feet 
per acre. Owing to various causes, not more than 50 to 75 per 
cent of this amount will reach the culvert within the same hour. 

Inches of rainfall X 3630 — cubic feet per acre. 

Inches of rainfall X 2,323,200 = cubic feet per square mile. 

(2) The amount of water to be drained off will depend upon 
the permeability of the surface of the ground, which will vary 
greatly with the kind of soil, the degree of saturation, the condi¬ 
tion of the cultivation, the amount of vegetation, etc. 

(3) The rapidity with which the water will reach the water¬ 
course depends upon whether the surface is rough or smooth, steep 
or flat, barren or covered with vegetation, etc. 

(4) The rapidity with which the water will reach the culvert 
depends upon whether there is a well-defined and unobstructed chan¬ 
nel, or whether the water finds its way in a broad thin sheet. If 
the water-course is unobstructed and has a considerable inclination, 
the water may arrive at the culvert nearly as rapidly as it falls; 
hut if the channel is obstructed, the water may be much longer in 
passing the culvert than in falling. 

(5) The area of the water-way depends upon the amount of the 
area to be drained; hut in many cases the shape of this area and 
the position of the branches of the stream are of more importance 
than the amount of the territory. For example, if the area is long 
and narrow, the water from the lower portion may pass through 
the culvert before that from the upper end arrives; or, on the 
other hand, if the upper end of the area is steeper than the 
lower, the water from the former may arrive simultaneously with 
that from the latter. Again, if the lower part of the area is 




DRAINAGE—CULVERTS. 


381 


better supplied with branches than the upper portion, the water 
from the former will be carried past the culvert before the arrival 
of that from the latter; or, on the other hand, if the upper portion 
is better supplied with branch water-courses than the lower, the 
water from the whole area may arrive at the culvert at nearly the 
same time. In large areas the shape of the area and the position 
of the water-courses are very important considerations. 

(6) The efficiency of a culvert may be materially increased by 
so arranging the upper end that the water may enter it without 
being retarded. The discharging capacity of a culvert can also be 
increased by increasing the inclination of its bed, provided the 
channel below will allow the water to flow away freely after having 
passed the culvert. 

(7) The discharging capacity of a culvert can be greatly in¬ 
creased by allowing the water to dam np above it. A culvrrt wi'l 
discharge twice as much under a head of four feet as under a head 
of one foot. This can be dene safely only with a well-constructed 
culvert. 

700. The determination of the values of the different factors 
entering into the problem is almost wholly a matter of jndgoent. 
An estimate for any one of the above factors is liable to be in error 
from 100 to 200 per cent, or even more, and of course any result 
deduced from such data must be very uncertain. Fortunately, 
mathematical exactness is not required by the problem nor wai- 
ranted by the data. The question is not one of 10 or 20 per cent 
of increase; for if a 2-foot pipe is insufficient, a 3-foot pipe will 
probably be the next size, an increase of 225 per cent; and if a (i- 
foot arch-culvert is too small, an 8-foot will be used, an increase of 
180 per cent. The real question is wdiether a 2-foot pipe or an 
8-foot arch-culvert is needed. 

701. Calculating Area of Water-way.—Numerous empirical for¬ 
mulas have been proposed for this and similar problems; but at 
best they are all only approximate, since no formula can give ac¬ 
curate results with inaccurate data. 

702. Mr. Rudolph Ilering, C.E., gives the following formula 
for calculating the size of the water-way for culverts and drains: 




382 


HIGHWAY CONSTRUCTION. 


in which 

Q = the number of cubic feet per acre per second reaching the 
mouth of the culvert or drain. 

C = a coefficient ranging from .31 to .75, depending upon the 
nature of the surface; .62 is recommended for general 
use. 

r = average intensity of rainfall in cubic feet per acre per 
second. 

S = the general grade of the area per thousand feet. 

A = the area drained, in acres. 

703. Valuable data on the proper size of any particular culvert 
maybe obtained (1) by observing the existing openings on the same 
stream; (2) by measuring, preferably at time of high water, a cross- 
section of the stream at some narrow place; and (3) by determining 
the height of high water as indicated by drift and the evidence of 
the inhabitants of the neighborhood. With these data and a care¬ 
ful consideration of the various matters referred to in Art. 674, 
it is possible to determine the proper area of water-way with a 
reasonable degree of accuracy. 

704. On mountain roads or roads subjected to heavy rainfall 
culverts of ample dimensions should be provided wherever required, 
and it will be more economical to construct them of masonry. In 
localities where boulders and other debris are likely to be washed 
down during wet weather, it will be a good precaution to construct 
catcli-pools at the entrance of all culverts and cross-drains for the 
reception of such matter. In hard soil or rock these catch-pools 
will be simple well-like excavations, with their bottom two or three 
feet below the entrance-sill or floor of the culvert or drain. Where 
the soil is soft they should be lined with stone laid dry; if very soft, 
with masonry. The size of the catch-pools will depend upon the 
widths of the drainage works. Thev should be wide enough to 
prevent the drains from being injured by falling rocks and stones 
of a not inordinate size. * 

The use of catcli-pools obviates the necessity of building cul¬ 
verts and drains at an angle to the axis of the road. Oblique 
structures are objectionable, as being longer than if set at right 
angles, and by reason of the acute- and obtuse-angled terminations 
to their piers, abutments, and coverings. 

705. Materials for Culverts.—Culverts may be of stone, brick. 



DRA IN A GE—C U L V E RTS. 


383 


vitrified earthenware, cement, or iron pipe. Wood should be ab¬ 
solutely avoided. 

For small streams and for a limited surface of rainfall either 
class of pipes, in sizes varying from 12 to 24 inches in diameter, will 
serve excellently. They are easily laid, and if properly bedded, 
with the earth tamped about them,are very permanent. Their upper 
surface should be at least 18 inches below the road-surface, and the 
upper end should be protected with stone paving so arranged that 
the water can in no case work in around the pipe. 

When the flow of water is estimated to be too great for two 
lines of 24-inch pipes, a culvert is required. If stone abounds, it 
may be built of large roughly squared stones laid either dry or in 
mortar. When the span required is more than 5 feet, arch-culverts 
either of stone or brick masonry may be employed. For spans 
above 15 feet the structure required becomes a bridge. 

706. Cement and Earthenware Pipe Culverts.— Construction .— 
In laying the pipe the bottom of the trench should be rounded 
out to fit the lower half of the body of the pipe with proper de¬ 
pressions for the sockets. If the ground is soft or sandy, the 
earth should be rammed carefully, but solidly in and around the 
lower part of the pipe. The top surface of the pipe should, as a 
rule, never be less than 18 inches below the surface of the roadway, 
but there are many cases where pipes have stood for several years 
under heavy loads with only 8 to 12 inches of earth over them. No 
danger from frost need be apprehended, provided the culverts are 
so constructed that the water is carried away from the level end. 
Ordinary soft drain-tiles are not in the least affected by the expan¬ 
sion of frost in the earth around them. 

The freezing of water in the pipe, particularly if more than 
half full, is liable to burst it; consequently the pipe should have a 
sufficient fall to drain itself, and the outlet should be so low that 
there is no danger of back-waters reaching the pipe. If properly 
drained, there is no danger from frost. 

Jointing .—In many cases, perhaps in most, the joints are not 
calked. If this is not done, there is liability of the waters being- 
forced out at the joints and washing away the soil from around the 
pipe. Even if the danger is not very imminent, the joints of the 
larger pipes, at least, should be calked with hydraulic cement, since 
the cost is very small compared with the insurance against damage 



384 


HIGHWAY CONSTRUCTION. 


ABUTMENTS FOR PIPE CULVERTS. 



W/, Wv* ,V\v\W'\V\vaV 


— W 


Ij 

« 


„J 

w5sw\ 


Fig: 93. 




Fig 94-. Fig.95 



Fig. 96, 





































































DRAINAGE—CULVERTS. 


385 


thereby secured. Sometimes the joints are calked with clay. 
Every culvert should be built so that it can discharge water under 
a head without damage to itself. 

The end sections should be protected with a masonry or timber 




bulkhead, although it is often omitted. A parapet wall of rubble 
masonry or brick-work laid in cement is best (see Fig. 93). The 
foundation of the bulkhead should be deep enough not to be dis¬ 
turbed by frost. In constructing the end wall, it is well to increase 
the fall near the outlet to allow for a possible settlement of the in¬ 
terior sections. When stone and brick abutments are too expensive, 
a fair substitute can be made by setting posts in the ground and 
spiking plank on, as shown in Fig. 95. When planks are used, it is 






















































































































386 


HIGHWAY CONSTRUCTION. 


best to set them with considerable inclination towards the roadbed 
to prevent their being crowded outward by the pressure of the 




Fig. 96d. SECTION OF PIPE CULVERT. 

embankment. The upper end of the culvert should be so protected 
that the water will not readily find its way along the outside 








































































































DRAINAGE—CULVERTS. 


387 


of the pipes, in case the mouth of the culvert should become 
submerged. 

When the capacity of one pipe is not sufficient, two or more 
may be laid side by side as shown in Figs. 96a to 96c. Although 
two small pipes do not have as much discharging capacity as a sin¬ 
gle large one of equal cross-section, yet there is an advantage in 
laying two small ones side by side, since the water need not rise so 
high to utilize the full capacity of the two pipes as would be neces¬ 
sary to discharge itself through a single one of larger size. 

707. Cost.—Price of earthenware and cement pipe vary greatly 
with the conditions of trade, and with competition and freight. 
Current (1892) prices, subject from 40 to 65 per cent discount for 
culvert-pipe in car-load lots, f. o. b. at the factory, are about as 
follows: 


TABLE LXXI. 

Cost and Weight of Vitrified Culvert-pipe. 


Inside Diameter. 
Inches. 

Price per foot. 
Cents. 

Area. 

Square feet. 

Weight per foot. 
Pounds. 

Number of feet 
in Car-load of 
24,000 lbs. 

12 

85 

.78 

48 

500 

15 

125 

1.23 

67 

358 

18 

170 

1.76 

84 

286 

20 

225 

2.18 

99 

242 

24 

325 

3.14 

140 

172 


TABLE LXXII. 

Cost and Weight of Portland Cement-pipe. 


Inside Diameter. 
Inches. 

Price per foot. 
Cents. 

Area. 

Square feet. 

Weight per foot. 
Pounds. 

* 

Number of feet 
in Car-load of 
24,000 lbs. 

12 

85 

.78 

57 

450 

15 

125 

1.23 

77 

320 

18 

178 

1.76 

no 

230 

20 

225 

2.18 

135 

180 

24 

325 

3.14 

165 

150 


708. Iron Pipe-culverts.—During recent years iron pipe has been 
used for culverts on many prominent railroads, and may be used on 
roads in sections where other materials are unavailable.. 


























388 


HIGHWAY COXSTRUCTIOX. 


In constructing a culvert with cast-iron pipe the points requir¬ 
ing particular attention are (1) tamping the soil tightly around the 
pipe to prevent the water from forming a channel along the outside, 
and (2) protecting the ends by suitable head walls and, when neces¬ 
sary laying riprap at the lower end. The amount of masonry re¬ 
quired for the end walls depends upon the relative width of the 
embankment and the number of sections of pipe used. For ex¬ 
ample, if the embankment is, say, 40 feet wide at the base, the 
culvert may consist of three 12-foot lengths of pipe and a light end 
wall near the toe of the bank; but if the embankment is, say, 32 
feet wide, the culvert may consist of two 12-foot lengths of pipe 
and a comparatively heavy end wall well back from the toe of the 
bank. The smaller sizes of jhpe usually come in 12-foot lengths, 
but sometimes a few 6-foot lengths are included for use in adjust¬ 
ing the length of the culvert to the width of the bank. The larger 
sizes are generally 6 feet long. 

709. Cost.—Prices of cast-iron pipe vary greatly with com¬ 
petition and the conditions of trade. Table LXXIII shows current 
prices (1892), subject to commercial discount: 


TABLE LXXIII. 

Dimensions, Weight, and Prices of Iron Pipe. 


Inside Diameter. 

Thickness. 

Weight per foot. 

Price per foot. 

12 inches 

3 % inch 

60 pounds 

96 cents 

16 

i t 

i << 

86 

( < 

140 “ 

20 

< i 

5 << 

8 

118 

« < 

188 “ 

.24 

< < 

B << 

F 

175 

( < 

280 “ 

30 

< < 

3 << 

T 

240 

(i 

384 “ 

36 

< i 

3 << 

¥ 

320 

a 

512 “ 

42 

< < 

7 «< 

8 

400 

(( 

640 “ 

48 

a 

1 “ 

510 

t c 

616 “ 


710. The approximate relative cost of the different forms of 
culvert per lineal foot for each square foot of waterway is as 
follows: 


follows: 

Rubble. 40 cents 

Earthenware or cement pipe. 30 “ 

Iron pipe. 4 @ “ 


711. Stone Box-culverts.—The simplest form of stone culvert 
is what is known as the box-culvert. It consists of two side walls, 



















DRAINAGE—CULVERTS. 


389 


EXAMPLES OF BOX-CULVERTS. 


J 


^ / ; 7/7/'. U ' 1 

il i 


COObllUOUUiZIj 

at,/// * /1 /,■m/rw/mi n w t v// aM 


1 


WV/w/r/j, vrrr 


tyn/nr?//rr'‘rr/'K7ft> 



Fig. 97.— End Elevation. 



Fig. 99—Plan, 


Fig, 98.— Section AB. 



Fig. 1 00.— Section CD. 



Fig. 1 01 —Section of Culvert on a Hillside. 













































































390 


HIGHWAY CONSTRUCTION. 


which may be built of stone laid dry or in mortar, and a covering 
of flags. Where large flat stones can readily be procured it forms 
a very economical structure. Under high embankments the thick¬ 
ness of the covering-stone must be increased. Figs. 97 to 101 show 
the form of this class of culverts and the dimensions given in 
Table LXXIV will serve as an approximate guide for general 
use. 


TABLE LXXIV. 
Dimensions for Box-culverts. 


Area. 

Opening. 

Side Wall. 

Depth of Cover. 

Length of Cover. 

4 feet 

2' X 2' 

2 X 2’ 

12 inches 

5 feet 

9 J< 

3X3 

3 X 2\ 

16 

< < 

6 “ 

16 “ 

4X4 

4X3 

20 

< ( 

7 “ 

25 “ 

5X5 

5 X 3| 

22 

a 

8 “ 

36 “ 

6X6 

6X4 

24 

i c 

9 “ 


712. Arch-culverts.—The form of an arch may be the semi¬ 
circle, the segment, or a compound formed of a number of circular 
curves of different radii. Full-centre arches or entire semicircles 
offer the advantages of simplicity of form, great strength, and small 
lateral thrust; but if the span is large they require a correspond¬ 
ingly great rise, which is often objectionable. The flat or segmental 
arch enables us to reduce the rise, but it throws a great lateral 
strain on the abutments. The compound curve gives, when prop¬ 
erly proportioned, a strong arch, with a moderate lateral action, is 
easily adjustable to different ratios between the span and the rise, 
and is unsurpassed in its general appearance. In striking the com¬ 
pound curve, the following conditions are to be observed: the 
tangents at the springing must be vertical, the tangent at the crown 
horizontal, and the number of centres must be uneven. 

713. The depth of the arch-stone, or thickness of voussoir, de¬ 
pends upon the form and size of the arch, the character of the 
masonry, and the quality of the stone. The following table gives 
the depths for semicircular arches, the second column being for 
hammer-dressed beds, the third for beds roughly dressed with the 
chisel, and the fourth for brick masonry. 















DRAINAGE—CULVERTS. 


391 


EXAMPLE OF ARCH-CULVERTS. 





F,g. 1 05.— Section CD. 












































































392 


HIGHWAY CONSTRUCTION". 


TABLE LXXV. 


Span in feet. 

Thickness of Arch in inches. 

First-class Masonry. 

Second-class Masonry. 

Brick Masonry. 

6 

12 

15 

12 

8 

13 

16 

16 

10 

14 

17 

20 

12 

15 

19 

20 

14 

16 

20 

24 

16 

17 

21 

24 

18 

18 

23 

24 

20 

19 

24 

24 

25 

20 

25 

28 

30 

21 

26 

28 

35 

22 

28 

28 

40 

23 

29 

32 

45 

24 

30 

32 

50 

25 

31 

32 


Professor Rankine remarks that the precise determination of 
the depth of the keystone of an arch would be an almost imprac¬ 
ticable problem from its complexity, and that the best course in 
practice is to assume a depth for the keystone according to an 
empirical rule founded upon the dimensions of good existing ex¬ 
amples of bridges. For such a rule he gives the following: 

Depth in feet = 4/(.12 radius at crown) for a single arch. 

Depth in feet = |/(.17 radius at crown) for an arch of a series. 
Mr. Trautwine gives the following rule: For first-class cut stone 
of hard material take 0.36 of the square root of the radius of the 
crown; for second-class work, .40 of the square root; and for brick 
or rubble arches, 0.45 of the square root. The results by the latter 
are slightly in excess of those by Professor Rankine’s formula. 

714. Thickness of Abutments.—Numerous rules have been given 
for obtaining the thickness of the abutments for arches. The 
most elaborate of these are from their form applied with difficulty to 
the cases commonly occurring in practice, and many of the elements 
entering into the solution of the problem are quite indeterminate, de¬ 
pending as they do upon the character of the masonry and upon 
the workmanship. In place of rules, therefore, we present merely 
an empirical table, embracing the results of a considerable degree 
of practice. 















DRAIKAGE—CULVERTS. 


393 


EXAMPLE OF ARCH-CULVERTS. 

I 




Fig. 1 08—SECTION AB. 














































394 


HIGHWAY CONSTRUCTION. 


Table LXXVI gives the minimum thickness of abutments for 
arches of 120 degrees where the depth of crown does not exceed 3 
feet. 

Calculated from the formula 



in which D = depth or thickness of crown in feet; 

H = height of abutment to springing in feet; 
R = radius of arch at crown in feet; 

T = thickness of abutment in feet. 


TABLE LXXVI. 

Minimum Thickness of Abutments for Arches of 120 Degrees 

WHERE THE DEPTH OF CROWN DOES NOT EXCEED 3 FEET. 


Span of 

Height of Abutment to Springing, in feet. 

Arch. 








5 

7.5 

10 

20 

30 

8 feet 

3.7 

4.2 

4.3 

4.6 

4.7 

9 

< i 

3.9 

4.4 

4.6 

4.9 

5.0 

10 

( ( 

4.2 

4.6 

4.8 

5.1 

5.2 

12 

t < 

4.5 

4.7 

5.2 

5.6 

5.7 

14 

( i 

4.7 

5.2 

5.5 

6.0 

6.1 

16 

( < 

4.9 

5.5 

5.8 

6.4 

6.5 

18 

( < 

5.1 

5.8 

6.1 

6.7 

6.9 

20 

4 4 

5.3 

6.0 

6.4 

7.1 

7.2 

22 

4 < 

5.5 

6.2 

6.6 

7.3 

7.6 

24 

it 

5.6 

6.4 

6.9 

7.6 

7.9 

30 

i i 

6.0 

7.0 

7.5 

8.4 

8.8 

40 

it 

6.5 

7.7 

8.4 

9.6 

10.0 

50 

if 

6.9 

8.2 

9.1 

10.5 

11.1 

60 

f i 

7.2 

8.7 

9.7 

11.4 

12.0 

70 

i t 

7.4 

9.1 

10.2 

11.8 

12.9 

80 

4 ( 

7.6 

9.4 

10.6 

12.8 

13.6 

90 

(( 

7.8 

9.7 

11.0 

13.4 

14.3 

100 

if 

7.9 

10.0 

11.4 

14.0 

15.0 


Note. —The thickness of abutment for a semicircular arch may be taken 
from the above table by considering it as approximately equal to that for an 
arch of 120 degrees having the same radius of curvature; therefore by divid¬ 
ing the span of the semicircular arch by 1.155 it will give the span of the 120- 
degree arch requiring the same thickness of abutment. 


I 




















DRAINAGE—CULVERTS. 


395 


TABLE LXXVII. 


Dimensions, Weight, and Prices of Drain-tile. 


Inside 

Diameter. 

Inches. 

Area in inches. 

Weight per 
foot. 

Price per 1000 
feet.* 

Curves and 
Reducers. 
Each. * 

No. Feet 
to 

Carload. 

2 

3.141 

3 

$15.00 

$0.20 

8000 

3 

7.068 

44 

25.00 

0.20 

6000 

4 

12.566 

64 

45.00 

0.25 

4000 

5 

19.625 

9 

75.00 

0.30 

3000 

6 

28.274 

12 

100.00 

0.40 

2200 

7 

38.484 

15 

110.00 

0.50 

2000 

8 

50.265 

22 

150.00 

0.70 

1250 

9 

63.617 

26 

200.00 

0.75 

1000 

10 

78.539 

33 

250.00 

1.00 

850 

12 

113.09 

44 

325.00 

1.25 

750 

15 

176.71 

60 

450.00 

1.50 

500 

18 

254.46 

92 

700.00 

2.25 

350 

20 

314.16 

106 

1000.00 

3.00 

250 

21 

345.00 

110 

1250.00 

4.00 

225 

24 

452.39 

150 

1625.00 

5.00 

200 


* Subject to discount. 


TABLE LXXVIII. 

Discharging Capacity of Circular Pipes in Cubic Feet per Minute. 


Diameter 

of 

Pipe. 


Inclination. Inches per 100 feet. 


3 

6 

9 

12 

24 

inches 

cu. ft. 

cu. ft. 

cu. ft. 

cu. ft. 

cu. ft. 

2 

1.71 

2.54 

3.07 

3.61 

4.95 

3 

3.07 

4.68 

5.34 

6.16 

8.56 

4 

6.28 

8.82 

10.82 

12.43 

17.51 

8 

35.42 

30.01 

61.49 

70.72 

100.26 

9 

47.46 

67.24 

82.48 

95.05 

161.23 

12 

97.59 

138.10 

170.18 

196.25 

277.54 

15 

171.37 

243.04 

297.32 

329.41 

483.55 

18 

270.32 

383,69 

468.98 

540.77 

749.18 

20 

327.54 

461.23 

558.82 

649.73 

914.43 

24 

555.08 

784.89 

962.83 

1176.87 

1570.05 
































CHAPTER XV. 


BRIDGES, RETAINING-WALLS, PROTECTION WORKS, TUNNELS, 

FENCING. 

715. Bridges .—The construction of bridges is an important 
subject, and should not be attempted without the professional ser¬ 
vices of a civil engineer. Neglect of this precaution, and an inad¬ 
equate conception by the people of the risks to their own and other 
persons' lives produced by faulty bridge design, are causes to which 
may be attributed many of the numerous failures of highway 
bridges annually recorded. 

As the subject is so extensive, but a few general remarks will 
be made in this volume. 

No one bridge is adapted to every situation; each one must be 
designed to sustain the amount and character of the load to which 
it will be subjected. 

716. All bridges should be proportioned to sustain the strains 
produced by the following loads: 

(1) The dead load , which is the weight of the structure itself, 
and in certain cases some extraneous loading. The dead load is 
taken as uniformly distributed over the bridge. 

(2) The live load. The live load on a bridge is the moving load 
passing over it. In calculating the dimensions of the several parts 
forming the superstructure of a bridge, the heaviest load which is 
likely to traverse it should be taken. 

Live loads are of varied character; they comprise the weight of 
loaded vehicles passing either singly or in continuous strings, por¬ 
table engines, agricultural machinery, steam road-rollers, and the 
weight of a crowd of people densely packed. 

(3) The wind-pressure, including both direct and indirect effects. 

(4) Variations of temperature. 

Valuable information on the subject of highway bridges is to be 

396 


BRIDGES, RETAINING-WALLS, TUNNELS, ETC. 


397 


found in the specifications for highway bridges of iron and steel 
by J. A. Waddell. 

717. Nothing improves the appearance and attractiveness of a 
road so much as a handsome bridge. And it need cost no more to 
construct than a homely, uncouth structure. 

718. Materials for Bridges.—Bridges may be either of stone, 
brick, wood, steel, iron, or iron and wood. For permanence and 
beauty, stone or stone and brick is preferable. Steel and iron make 
handsome bridges, but require more attention than stone. Wood 
is the least permanent, and cheapest in first cost. 

719. Timber Bridges.—In many localities timber is the only 
material available for bridges. Therefore a few directions for their 
construction may be useful. The simplest form of wooden bridge 
is that of plain stringers laid across the stream and covered with 
plank. The width of the openings which such beams span should 
not exceed 16 feet. For greater widths, supports in the form of 
piles may be introduced, thus dividing the long span into a number 
of shorter ones; but such supports are obstructions to the stream 
and liable to damage in time of freshets. It is, therefore, desirable 
to avoid their use. Other forms of support must therefore he 
devised for strengthening the beams. This may he effected by 
supports from below or above. Of supports from below, the sim¬ 
plest are shorter timbers (bolsters or corbels) placed under the 
main ones to which they are firmly bolted, and projecting about 
one third of the span. 

Still more effective are oblique braces or struts supporting the 
middle of the beam, and resting at their lower ends in shoulders 
formed in the abutments. Similar braces may be applied to the 
bolsters (Fig. 113); but as the span increases, these braces become 
so oblique as to lose much of their efficiency. A straining-piece 
is therefore interposed between them. Openings up to thirty-five 
feet may thus be spanned. 

For longer spans, the bolsters, braces, and straining-beams may 
be combined as in Fig. 114. The principle of this method may be 
extended to very wide openings. 

But in many cases supports from below may be objectionable, 
as exerting too much thrust against the abutments, and being liable 
to be carried away by freshets, etc. The beams must in such cases 
be strengthened by supports from above. 



398 


HIGHWAY CONSTRUCTION", 


TYPES OF TIMBER BRIDGES. 



Tig-109. 



Fig-117. 


W, 


! 


Fig.no. 




m 


1 


Fig. Ill 







HEAVY LINES WOOD. LIGHT LINES IRON. 
















































































BRIDGES, RETAINING-WALLS, TUNNELS, ETC. 


399 


The simplest form of such is shown in Fig. 115, in which the 
horizontal beam is supported by an upright “ king-post” to which 
it is attached by an iron strap, or by the upright “ king-post” being 
formed of two pieces bolted together, and enclosing the beam be¬ 
tween them. The king-post itself is supported by the oblique braces, 
or struts, which rest against notches in the horizontal beam. 

Since the king-post acts as a suspending tie, an iron rod may be 
advantageously substituted for it; the struts may be also stilfened 
by iron ties, binding them to the main timbers as in Fig. 116. 

For longer spans, a straining-beam may be introduced between 
the struts as in Fig. 121, in which the posts are represented as en¬ 
closing the beam. 

The diagrams of simple bridges. Figs. 125 to 132, and Tables 
LXXIX and LXXX give the spans for which they may be em¬ 
ployed and the dimensions of the several parts. 

Fig. 129 show T s the iron washer used at the end of the beam. 
The latter should be at right angles to the direction of the 
rod. It is better to have two rods instead of one rod under each 
beam. This allows the rods to be outside of the beam, as shown 
in the figure, instead of requiring holes to be bored through it, 
thereby weakening it. Fig. 130 shows the shoe used at the foot 
of the post and which holds the rods in place. Figs. 131 and 132 
show the same method of construction applied to bridges of greater 
width and span. 

Combination structures of wood and iron require constant 
watchfulness, to repair and replace damages arising from decay or 
defective material. 

Iron Bridges.—The first cost of iron or steel bridges is greater 
than that of wood or combination structures; but where economy 
of the public funds is desired, the first two materials are to be pre¬ 
ferred, because the annual cost of repairs to the wooden structure 
will in a very few years equal, if not greatly exceed, the additional 
sum required for the construction of the all-metal bridge. More¬ 
over, the metal structure will outlive two if not more timber ones. 

Figs. 132$, 132 b, 132c show types of iron bridges. 

To ascertain the saving in favor of iron, see Chapter XXIII. 

720. The substructures of bridges should be of masonry. Tim¬ 
ber should not be used if it can possibly be avoided. Such struc- 



400 


HIGHWAY CONSTRUCTION. 





^ ^ r>r>T> ^3 


A If El 




£2!M 


W-,-- 

\A 



\ — 



Fig. 126. TRANSVERSE SECTION. 


TABLE LXXIX. 

Dimensions for Figs. 125 and 126. 


Span. 

Feet. 

Girders. 

Inches. 

Floor-beams. 

Inches. 

Floor. 

Inches. 

Railing. 

Inches. 

5 

8 X 10 

6X6 

4 

3X4 

10 

10 X 14 

f f 

< i 

a 

15 

12 X 18 

i i 

ft 

< i 

20 

14 X 22 

U 

it 

it 



Fig. 127. LONGITUDINAL SECTION. 






























































BRIDGES, RETAINING-WALLS, TUNNELS, ETC. 


401 



Fig. 128. TRANSVERSE SECTION. 




Fig. 129. 

DETAIL OF WASHER. 



Fig. 130. 

DETAIL OF SHOE. 


TABLE LXXX. 

Dimensions for Figs. 127 to 132. 


Span. 

Feet. 

Girders. 

Inches. 

Diameter of Rods. 
Inches. 

Post. 

Inches. 

15 

12 X 15 

1 T(T 

3 X 12 

20 

12 X IS 

113 

■*•16 

3 X 12 

25 

14 X 18 

2 

3 X 14 

30 

15 X 20 

9, 3 
~'TS 

4 X 15 



Fig. 131. LONGITUDINAL SECTION. 














































































402 


HIGHWAY CONSTRUCTION, 


tures are unsatisfactory owing to early decay caused by the destroy¬ 
ing action of air and water. 

o • p • 

For directions and specifications for the construction of iron 



Fig. 132. TRANSVERSE SECTION. 


and steel highway bridges the excellent specifications of Messrs. G. 
Bouscaren, Theodore Cooper, Edwin Thacher, and J. A. Waddell 
may be consulted. 

721. Retaining-walls. —Retaining-walls are structures of stone 
laid dry or in mortar, and are employed under various forms to sup¬ 
port the sides of roads on hillsides, or places where land for the 
slopes is not obtainable (see Figs. 133 to 136). 

722. Thickness of Walls. —Retaining-walls require a certain 
thickness to enable them to resist being overthrown by the thrust 
of the material which they sustain. The amount of this thrust 
depends upon the height of the mass to be supported and upon the 
quality of the material. 

723. Surcharged Walls. —A retaining-wall is said to be sur¬ 
charged when the bank it retains slopes backwards to a higher 
level than the top of the wall; the slope of the bank may be either 
equal to or less, but cannot be greater, than the angle of repose of 
the earth of the bank. 

724. Proportions of Retaining-walls. —In determining the pro¬ 
portions of retaining-walls experience, rather than theory, must be 
our guide. The proportions will depend upon the character of the 
material to be retained. If the material be stratified rock with in- 











































403 





































































































































































































































404 


HIGHWAY CONSTRUCTION 










































































































































































































BRIDGES, RETAINING-WALLS, TUNNELS, ETC. 


405 


terposed beds of clay, earth, or sand, and if the strata incline 
toward the wall, it may require to be of far greater thickness than 



Fig. 133. 





>\W’ 


Fig. 134. 




any ordinary retaining-wall; because when the thin seams of earth 
become softened by infiltrating rain, they act as lubricants, like 































406 


HIGHWAY CONSTRUCTION. 


soap or tallow, to facilitate the sliding of the rock strata; and thus 
bring an enormous pressure against the wall. Or the rock may be 
set in motion by the action of frost on the clay seams. Even 
if there be no rock, still if the strata of soil dip toward the wall, 
there will always be danger of a similar result; and additional pre¬ 
cautions must be adopted, especially when the strata reach to a 
much greater height than the wall. 

725. Form of Retaining-walls.—Retaining-walls are built of 
numerous forms of profile or cross-section, varying from the rect¬ 
angular to the triangular. A triangle is that figure which is 
theoretically the most economical; and the nearer that practical 
conditions will allow of its being conformed to the better. 

All other things being equal, the greater the face-batter the 
greater will be the stability of the wall; but considerations con¬ 
nected with the functions of the wall limit the full application of 
this condition, and walls are usually constructed with only a 
moderate batter on the face, the diminution towards the top being 
obtained by a back batter worked out in a series of offsets. Walls 
so designed contain no more material and present greater resist¬ 
ance to overturning than walls with vertical backs. 

726. Dry stone retaining-walls are best suited for roads on ac¬ 
count of their self-draining properties and their cheapness. If 
these dry walls are properly filled in behind with stones and chips, 
they are, if well constructed, seldom injured or overthrown by 
pressure from behind. If the stone is stratified with a flat cleav¬ 
age, the construction of retaining and parapet walls is much facili¬ 
tated. If the stone has no natural cleavage, great care is necessary 
to obtain a proper bond. If walls built of such stone are of 
coursed rubble, care is required that the masons do not sacrifice 
the strength of the walls to the face appearance. The practice of 
building walls with square or rectangular-faced stones, tailing off 
behind, laid in rows, one course upon the other, the rear portions 
of the walls being of chips and rough stones, set anyhow, cannot 
be condemned too strongly. Such a construction, which is very 
common, has little transverse and no longitudinal strength. 

Little or no earth should be used for back filling if stone is 
available. Where earth filling is used, it should only be thrown in 
and left to settle itself; on no account should it be wetted and 
rammed. 




BRIDGES, RETAINING-WALLS, TUNNELS, ETC. 


407 


The foundation of retaining-walls should he particularly 
secure; the majority of failures which have occurred in such walls 
have been due to defective foundations. 

727. Failure of Retaining-walls.—Retaining-walls generally 
fail (1) by overturning or by sliding, or (2) by bulging out of the 
body of the masonry. Sliding may be prevented by inclining tho 
courses inward. An objection to this inclination of the joints in dry 
walls is that rain-water, falling on the battered face, is thereby 
carried inwards to the earth backing, which thus becomes soft and 
settles. This objection may be overcome by using mortar in the 
face-joints to the depth of a foot, or by making the face of the 
wall nearly vertical. 

728. Protection of Retaining-walls.—The top of the walls should 
be protected with a coping of large heavy stones laid as headers. 

Where springs occur behind or below the wall, they must be 
carried away by piping or otherwise got rid of. 

The back of the wall should be left as rough as possible, so as 
to increase the friction of the earth against it. 

729. Weep -holes.—In masonry walls, weep-holes must be left 
at frequent intervals, in very wet localities as close as 4 feet, so as 
to permit the free escape of any water which may find its way to 
the back of the wall. These holes should be about 2 inches wide 
and should be backed with some permeable material, such as gravel, 
broken stone, etc. 

730. Formula for calculating Thickness of Retaining-walls.— 

E = weight of earth-work per cubic yard. 

W = weight of wall. 

II = height of wall. 

T — thickness of wall at top. 

T — II X tabular number (Table LXXXI). 

731. Surcharged Walls.—In calculating the strength of sur¬ 
charged walls substitute Y for II, Y being the perpendicular at 
the end of a line, L = H measured along the slope to be retained 
(Fig. 136). 

Y = 1.71//in slopes of 1 : 1; 

= 1.55// “ “ “ H : 1; 

= 1.35 n u “ “ 2 : 1; 

= 1.31 H “ “ “ 3 : 1; 

= 1.24// “ “ “ 4 : 1. 




408 


HIGHWAY CONSTRUCTION. 


TABLE LXXXI. 

Coefficients for Retaining-walls. 


Batter of Wall. 

E : W 

:: 4 : 5 

E : W 

:: 1 : 1 

Clay. 

Sand. 

Clay. 

Sand. 

1 ill 4 

.083 

.029 

.115 

.054 

1 in 5 

.122 

.065 

.155 

.092 

1 in 6 

.149 

.092 

.183 

.118 

1 in 8 

.184 

.125 

.218 

.153 

1 in 12 

.221 

.160 

.256 

.189 

Vertical 

.300 

.239 

.336 

.267 


732. Retaining-walls of dry stone should not be less than 3 feet 
thick at top, with a face of 1 in 4 and back perpendicular, the 
courses laid perpendicular to the face-batter. Weep-holes are 
unnecessary unless the walls are in very wet situations. 

Retaining-walls of masonry should be at least 2 feet thick at 
top, back perpendicular and face battered at the rate of 1 in 6. 

733. On steep hillside or mountain roads retaining-walls 
should be built— 

(1) At all re-entering curves. 

(2) At all culverts and bridges. 

(3) On the edge of precipitous places, where there is no room 
for a bank. 

(4) Where the bank slope and the ground slope are nearly or 
quite parallel to each other. 

(5) Where a hank would he of excessive length owing to the 
angle of the natural ground slope. 

(6) Where a wall would be cheaper than a bank. 

Retaining-walls on the edge of dangerous precipices, having to 

support great weight, should be built of masonry. All others may 
be of dry stone. 

734. Protection of Roads.—All roads should be protected, but 
hillside and mountain roads which are unprotected can only he 
classed as dangerous. Blocks of stone of not less than 2£ to 3 
feet in height, and set with not more than 3 feet between them, 
afford a fair protection on a mountain road not very precipitous 


















BRIDGES, RETAINING-WALLS, TUNNELS, ETC. 


409 


at its outer edge, and there is an advantage attendant upon their 
use that no outer gutter is necessary, for the drainage passes over 
the bank in every direction, and after the first year or two but 
little damage occurs to the banks from this cause. 

735. The proper amount of protection required for the danger¬ 
ous portions of a mountain road is best obtained by stone parapets 
and earthen mounds. Parapets should not be less than 3 feet in 
1 eight and, if of masonry, H feet in thickness. 

If stone parapets be built dry, they should be at least 2 feet in 
thickness, and the coping should be set in mortar; otherwise they 
are too easily deranged, and cartmen halting on the road and 
desiring to block the wheels of their vehicles invariably resort to 
them for a stone for this purpose. Next in order of protection 
afforded by the use of stone may be mentioned the plan of placing 
large blocks of r ough stone and boulders on the edge of the road 
and touching each other. If of good size and well set, considerable 
protection is afforded by this method, which is cheap. Dry stone 
parapet walls should never be employed if masonry walls can be 
afforded, and should on no account be used on precipitous curves. 
Parapets should be employed to protect all embankments of a road 
which have stone-wall revetments, and the outside of all cuttings 
in rock. They should also be built on each side of the road at all 
cross-drainage works, and should be adopted at all situations where 
stone is available from cuttings. Where the embankments are of 
earth, earthen mounds are to be preferred on the score of economy. 
These earthen mounds should uot be less than 3 feet in height, and 
they are best formed, both for appearance and for their own preser¬ 
vation, by being revetted with dry stone inside. Earthen mounds 
constructed in this manner afford the most secure protection for 
traffic, as, if well rounded off on the outer side, they do not yield to 
any concussion, however violent. 

736. Wooden railings should never be employed to protect dan¬ 
gerous places on a mountain road. They afford no real protection 
to the traffic, but only give a sense of protection to passing vehicles 
which do not come into collision with them, and show to unexcited 
animals that the w r ay is barred in that direction. 

737. Besides the protection so necessary for the safety of the 
travelling public, the roads themselves require protection at their 





410 


HIGHWAY CONSTRUCTION. 


edges from passing vehicles. Cart-wheels, if not prevented from 
hugging the very edge of the road, and from slipping, either from 
design or accident, into the gutters, do great damage. Curb-stones 
get forced out of their places, and if one be displaced, others soon 
follow, to the destruction of the road edge as well as of the gutters 
themselves. These become blocked with loose stones, and when 
rain falls greater destruction to the road ensues. It is necessary, 
therefore, to protect the edges of mountain roads where they are 
likely to be damaged by wheel traffic, which occurs chiefly on the 
inside of salient and outside of re-entering curves. 

738. Guard-stones about 9 inches square and of sufficient length 
should be placed every 4 or 5 feet apart at the curbs, clear of the 



gutter, on the hill side of salient curves. The re-entering curves 
must also be protected on the inner curve, which is the outer side 
of the roadway, by means of similar guard-stones, which, however, 
in this situation are set up in the gutters themselves. 

739. Roads along the seashore, margin of rivers and lakes, may 
be constructed according to either of the methods shown in Figs. 
137 to 139. 

In Fig. 137, two rows of piles, spaced about 10 feet centre to 
centre, are driven, one row along the toe of the slope and another 
along the crest of the slope, and capped with a 3-incli plank; be¬ 
tween each pile and fastened thereto a 4 X 6 inch or heavier stringer 
is placed. On these stringers a layer of matched tongued and 
grooved plank 2 or 3 inches thick are laid and spiked. 

In Fig. 138 a bulkhead is formed as follows: a row of piles, 
spaced 6 feet centre to centre, is driven to a solid bearing and 
capped with a heavy stick of timber. To the piles waling-sticks 
are bolted, one immediately at the head, the other at or below the 



















BRIDGES, RETAINING-WALLS, TUNNELS, ETC. 


411 


natural surface of the beach; on the land side of the waling-sticks 
matched sheet-piling is driven and spiked to the upper waling- 
stick. Anchor-piles are driven on the land side at such distance 
from the main piles as will form an angle of from 30 to 45 degrees. 
The main piles may be fastened to the anchor-piles by wrought- 
iron tie-rods, and bevelled cast-iron washers or timber may be used 



Fig. 1 38. 


for the same purpose. A brace-stick of either round or square 
timber should be placed in the angle formed between the tie-rod 
and head of the anchor pile. The face of the main piles at high- 
water mark should be protected by a chafing-stick. Fender-piles 
may also be used if the water is navigable for large boats. 



In Fig. 139 a masonry wall is shown, built on a timber plat¬ 
form. To this class of work the same rules apply as to retaining- 
walls. 

740. Tunnels.—For highways, generally no tunnels can be al¬ 
lowed. They are too costly, and can only be employed under 




















































412 


HIGHWAY CONSTRUCTION. 


exceptional circumstances. If a tunnel would shorten the road 
by a length, the cost of which would equal, or nearly so, the 
extra cost of the road through the tunnel, the construction of the 
tunnel would be justified. The saving in tractive energy to the 
public using the road would, in most cases, be a saving too indirect 
to be imported into the calculation. 

741. Fencing.—Fences are usually built by the property-owners, 
but occasionally the road-builder is called upon to include fencing 
in his work; therefore the following few remarks may be useful. 
The common post and rail fence is too well known to require de¬ 
scription; iron wire for fencing is to be had in an almost infinite 
variety; where stone abounds an excellent fence may be formed of 
the stones laid dry, with a rough coping formed of stones set edge¬ 
wise in mortar. The mound and ditch shown in Fig. 140 is much 
used in Europe. The material excavated from the ditch is thrown 



into the mound and a quickset hedge planted along the top. After 
the lapse of some time this makes a good fence; but it requires in 
the interim a considerable amount of repair. 

742. Cost of Fencing.—Wire, plain or barbed, with wood posts, 
generally cedar, chestnut, or oak, is much used in the United 
States. 

The posts cost 10 to 25 cents each, according to distance trans¬ 
ported. 

A 4-strand wire fence with posts set 3 feet in the ground and 
costing 15 cents each costs per mile from $200 to $250. 

Common board fence, posts set 8 feet apart, costs from $350 to 
$400 per mile. 

An estimate for a mile of barbed-wire fence would be about as 
follows: 






BRIDGES, RETAINING-WALLS, TUNNELS, ETC. 


413 


350 posts, including braces, at 10 cents.$35.00 

1500 pounds 4-pointed barbed wire, at 6 cents. 90 00 

40 pounds of staples, at 6 cents. 2.40 

Labor. 36.86 

Freight, tools, superintendence. 3.07 


Total.$167.33 


Fences formed of braided, woven, and crimped steel wire sup¬ 
ported by steel posts, and wrought-iron pipe and steel posts, are 
being extensively used for parks, pleasure-grounds, etc. The ma¬ 
terials are wrought in artistic forms and make strong, durable, 
and handsome fences. The price ranges from 12^ cents to $1.00 per 
foot. 

743. Specification for Fencing.—Posts to be oak or tamarack, 
5 inches in diameter and not more than 3 inches out of straight, 
8 feet 6 inches long, set 3 feet 6 inches in the ground, and spaced 
16J feet centre to centre. 

Height of fence 4 feet 9 inches, formed of four strands of wire 
placed 12, 14, 15, and 16 inches apart, measuring from the ground. 










CHAPTER XVI. 


CITY STREETS. 

744. The first work requiring the skill of the engineer is to 
properly lay out town sites, especially with reference to the future 
requirements of a large city where any such possibility exists. Few 
if any of our large cities were so planned. The same principles to 
a limited extent are applicable to all towns ’or cities. The topo¬ 
graphy of the site should be carefully studied and the street lines 
adapted to it; they should be laid out systematically with a view to 
convenience and comfort, also with reference to economy of con¬ 
struction, future sanitary improvements, grades, and drainage. 

745. Arrangement of City Streets. —Generally straight lines, 
with frequent and regular intersecting streets, is the best method 
of laying out streets, especially for business parts of a city. 
When there is some centrally located structure, such as court¬ 
house, city hall, market, or other prominent public building, it is 
very desirable to have several diagonal streets leading thereto. In 
the residence portions of cities, especially if on hilly ground, curves 
may replace straight lines with advantage by affording better 
grades at less cost of grading, and improving property by avoiding 
heavy embankments or cuttings. 

746. The rectangular arrangement of streets as seen in New 
York and other cities is being found objectionable and a bar to 
convenient communication; it therefore becomes necessary to 
examine what other systems, if any, may be used, and determine 
their relative merits. The following investigation of this subject 
by Mr. Lewis M. Haupt, A.M.C.E., Professor of Civil Engineering, 
University of Pennsylvania, is very interesting, as showing what 
may be done in the way of opening diagonal streets: 

The systems may be divided into two classes: 1st, regular, and 
2d, irregular. The first class may be subdivided into rectangular, 
diagonal, and circular; the second into every possible kind of dis- 

414 


CITY STREETS. 


415 


tortion more or less intricate, according to the circumstances at¬ 
tending the growth of a city. The latter class is discarded as being 
unscientific, expensive, inconvenient, and poorly adapted to the 
requirements of a growing community. 

“ As people move through a city in every conceivable direction, it 
will be impossible to provide.the shortest lines for all; but the case 
may be met by supposing a greater or less number of centres or 
points d’appui, to and from which the currents of daily life flow 
and ebb. 

“ With reference to the subdivision of the first class, it is evident 
that, the straight line being the shortest distance between two 
points, the chord will be shorter than its arc, and hence the circular 
system is defective. The rectangular compels a waste of distance 
and time, and the diagonal by itself becomes the rectangular, so 
that no single system fulfils all possible requirements. A combina¬ 
tion must therefore be resorted to, and that composed of right-line 
elements is both the simplest and most direct. A judicious ar¬ 
rangement of diagonal streets with the rectangular system will 
doubtless be found to meet more fully than any other the require¬ 
ments of the case; but it is evident that if the streets be too wide or 
too numerous, the building areas will be correspondingly decreased 
and a certain proportion of people forced beyond given limits, thus 
increasing their distances. On the other hand, the diagonals will 
in general open new building lines with more than residences 
enough to provide for all the displaced inhabitants. 

“To illustrate the utility of such a combination, suppose a 
portion of a town or city to be laid out in the form of a square 
whose side is L feet long, and in which the blocks are l feet square 
and the streets w feet wide. 

“ Let the diagonals of the large square be opened as thorough¬ 
fares, and note their effect. The blocks or small squares extend 
from the middle of one street to that of its parallel, or from the 
building line of one block to that of the next; hence the length of 
a side of such a square must be l +w (Fig. 14 la). 

« The area of the small square, including the streets, multiplied 
by the number of such squares will give the area U of that portion 
of the city, and the ratio of street to property area is the same for 
the small as for the large squares; but the area of the small squares 
is ( l -j- wY = l\ + 2 Iw + w 2 , in which F is the property or build- 




416 


HIGHWAY CONSTRUCTION. 


. 2 Iw + w 2 

ing area, and 2 Iw + w* is the street area; the ratio being-^- 

and the percentage of street to property area. 


2 Iw -f 


100 




//—--- 

Q Fig. 141. ARRANGEMENT OF CITY STREETS. N 


For any rectangle with streets of unequal widths, the general 
formula would be 

be -f- ad -f- del 
ac 



in which a and c are the sides of the rectangle and b and d the 
widths of the streets. If these quantities are equal, each to each 


































































































































































































































































































































































































CITY STREETS. 


417 


(A 1 ) becomes (A). The number (n ) of blocks in a given square 
whose area is U will be 


U 

(i + wy ~ 



“ If now two diagonals, MN and PQ be introduced, it is evident 
that where they cross the rectangular streets no additional area is 
taken from the private property of the city, but they will cut out of 


_J I_I L 



Fig. 141«. 


J I_I L_ 



each of the small squares which they cross an area whose length is 
4/2r — —, breadth w, and whose area for one block, l , is 

hJ 

(a/ZP _ |(see Fig. 141&). For n blocks the total building area 
consumed from V by both diagonals when n is even will be 
2 niv [VW - and the percentage of the building area will be 

% nw _ (— - ) X 100, which reduces to 

wV \ 2 / - 


-^•(2.828/ — w)100, 
nl 



()i$ formula for diac/onals whsu n is even. If u bo odd , Ct becomes 

—-(2.828^)100 = 282.8 . . (O'l 


























418 


HIGHWAY CONSTRUCTION'. 


“ If diagonals be opened, benefits will accrue both from the short¬ 
ening of distance and the additional frontage which will be fur¬ 
nished, while but a small proportion of the inhabitants will be 
displaced. The greatest economy in distance will be in passing 
from M to 0 (Fig. 141), which by the square system is equal to L , 

, ,,, ,. , ta/T ^ • LVl " 1.4142 70 

and by the diagonal LX b, the ratio being ——g— = the 


numerator indicating the distance (in feet) by the diagonals, the 
denominator by the squares. This gives a gain of 30 per cent, 
which is the greatest amount possible, and from which it diminishes 
to zero at P. 

“ The total length of frontage on the streets in the square system 

is 4 hi 2 . The diagonals give an additional length of — w), 

and the percentage of increase is therefore 


w inn 

In 



“ The ratio of people displaced is the same as that of the area 
consumed by diagonals to the entire area A 2 . 

“ To determine these values for any particular case, and so dis¬ 
cover whether or not the diagonals will be beneficial, let l = 500 
feet, w = 50 feet, and n = 10. 

“ Formula (A) gives 21 as the percentage of large or small 
squares consumed by streets in the rectangular system. 

“ Formula (C) gives only 2.82 per cent of additional building 
area consumed by diagonals. 

“ formula (D) gives 13 per cent as the increase in frontage due 
to diagonals, and it has been shown that the saving of distance 
varies from 30 per cent to nothing. 

“ The number of people displaced, which is only 2.82 per cent, 
will be abundantly provided for by the additional frontage on the 
diagonals, revenues will be augmented by assessments on the new 
buildings erected, and a large saving will be effected in time and 
distance for a majority of the inhabitants by this combination of 
systems, which is therefore found to fulfil the requirements of 
practice more fully than any other. 

“ Similar applications of the above formula will show to what 
extent the plans of cities already established or to be built may be 








CITY STREETS. 


419 


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unjzhan 


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JDL 


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ram 


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Fig. 142. ARRANGEMENT OF STREETS (PART OF 

WASHINGTON, D. C.) 































































































































































































































































































420 


HIGHWAY CONSTRUCTION. 


improved by the opening of diagonals; the most economical relation 
of street to building area, the proper distribution of the street area^ 
and, by extending the analysis, the ratio of pavement to carriageway 
may also be readily determined. All of these questions have a 
direct bearing on the convenience, health, and extension of our 
cities.” 

Fig. 142 shows the system adopted in laying out the streets of 
Washington, D. C. 

747. Width of Streets.— The width of streets should be propor¬ 
tioned to the character of the traffic that will use them; but, as a 
rule, this 1 as not been considered in the laying out of cities, and 
the width of the commercial thoroughfares is now found insufficient 
to properly accommodate the traffic. 

No rule can be laid down by which to determine the best width 
of streets; but it may be safely said that a street which is likely to 
become a commercial thoroughfare should have a width of not less 
than 120 feet between the building lines—the carriage-way 80 feet 
wide, and the sidewalks 20 feet each. 

In streets occupied entirely by residences a carriage-way 32 feet 
wide will be ample, but the width between the building lines may 
be as great as desired. The sidewalks may be any amount over 10 
feet which the fancy may dictate. Whatever width is adopted for 
them, not more of it than 8 feet need be paved, the remainder 
being occupied with grass and trees. 

Wide streets add materially to the commercial prosperity of the 
inhabitants of a city by relieving them of the heavy tax imposed 
by narrow streets on transportation through constantly recurring 
blockades. 

Wide streets afford a good amount of breathing space, and thus 
add to the general health of the people. Moreover, they contribute 
to a city an air of spacious comfort and dignified distance, and 
for all time remove from it the crowded appearance which is too 
commonly found in all old cities and towns. 

748. The maximum and minimum width of streets, with the 
average width of sidewalks and maximum grade, as at present es¬ 
tablished in various cities, are given in Table LXXXII. 

749. Street Grades.— Following the location of streets, there is 
the important duty of establishing a comprehensive system of 
grades. If this could always be done in advance of improvements, 



I 


CITY STREETS. 421 

there would be little difficulty in obtaining the best grades for a 
city. Unfortunately this is seldom the case, and in adjusting the 
street grades of villages in process of transformation into towns the 
engineer encounters one of his most trying duties; he meets much 
opposition from the property-owners who have made improvements 
based upon the natural slopes, also from those who object to having a 
street in excavation where it passes through their lands. Each one 
is looking to his individual interest, and he must exercise much dis¬ 
cretion and endeavor to fix a system of grades harmonious, conven¬ 
ient, and economical for the public rather than for individuals. 

Every town that expects to thrive should at a very early stage in 
its history establish the grades of its streets to the full extent of 
the town plot, and in doing so keep in view the probability of 
future extension. In new towns this ought to be done when the 
town is laid out, and the grades might be made part of the original 
record. 

750. No rule can be laid down for determining the proper 
grades for city streets. They will depend upon the topographical 
features of the site. The necessity of avoiding deep cuttings or high 
embankments which would seriously affect the value of adjoining 
property for building purposes often demands steeper grades than 
are permissible on country roads. There are, however, certain con¬ 
ditions which it is important to attain: first, that the longitudinal 
crown level be uniformly sustained from street to street whenever 
practicable, so as to avoid undulations; second, that the crown level 
at all intersections be extended transversely to avoid the necessity of 
driving over a channel, which is otherwise formed. 

Table LXXXII shows the maximum grade of streets in several 
cities. 

751. The best arrangement of intersections of streets when 
either or both have much inclination is a matter requiring much 
consideration and is one upon which much diversity of opinion 
exists. No hard or fast rule can be laid down; each will require 
special adjustment. The best and simplest method is to make the 
rectangular space aaaaaaaa , Fig. 143, level with a rise of one-half 
inch in 10 feet from AAAA to B, placing gulleys at AAAA and the 
catch-basins at cccc. When this method is not practicable, adopt 
such a grade (but one not exceeding 2| per cent) that the rectangle 
AAAA , Fig. 143, shall appear to be nearly level; but to secure this 







422 


HIGHWAY CONSTRUCTION 


TABLE LXXXII. 

Width of City Streets. 


City of 


New York, N. Y. 

Brooklyn, N. Y. 

Buffalo, N. Y. 

Syracuse, N. Y . 

Elmira, N. Y . 

Schenectady, N. Y. 

Boston, Mass. 

Lynn, Mass. 

Worcester, Mass. 

Lowell, Mass. 

Cambridge, Mass. 

Chicago, Ill. 

Bloomington, Ill. 

Jersey City, N. J. 

Camden, N. J. . 

Newark, N. J. 

Trenton, N. J. 

Paterson, N. J. 

Terre Haute, Ind. 

Richmond, Ya. 

Omaha, Neb. 

Nashville, Tenn . 

Parkersburg, W. Va. 

Washington, D C. 

Wilmington, N. C. 

Seattle, Wash. 

Philadelphia, Pa. 

Pittsburg, Pa. 

Erie, Pa. 

Harrisburg, Pa... 

Providence, R. I. 

Cumberland, Md. 

Hartford, Conn . 

Waterbury, Conn....... 

New Haven, Conn. 

Detroit, Mich... 

Grand Rapids. Mich. 

St. Paul, Minn. 

Minneapolis, Minn. 

Bucyrus, Ohio. 

Salt Lake City, Utah. 

Ogden, Utah. 

Burlington, Yt. 

Rutland, Vt. . 

Milwaukee, Wis. 

* London, Eng. 

* Birmingham, Eng. 


Width of Streets 
between Building Lines. 


Maximum. 

Feet. 

Minimum. 

Feet. 

100 

60 

100 

60 

100 

40 

120 

33 

100 

33 

90 

20 

100 

50 

100 

20 

70 

30 

102 

26 

150 

30 

100 

30 

80 

30 

100 

26 

132 

40 

80 

30 

120 

40 

99 

50 

118 

30 

120 

40 

104 

20 

60 

40 

160 

80 

99 

30 

120 

60 

120 

30 

100 

30 

100 

50 

120 

20 

225 

10 

65 

20 

70 

25 

160 

28 

100 

40 

120 

36 

100 

50 

200 

50 

120 

60 

824 

40 

132 

50 

132 

60 

99 

28 

99 

494 

100 

60 

80 

12 

80 

15 


Maximum 
Grade. 
Feet per 
100 feet. 

Average Width of 
Sidewalks. 

Feet. 

13 

15 

12 

18 

7 

23 

20 


5 

14 

8 



7 

17.21 

8 

20 

17 

16 

14 

11.66 

8 

2.40 

25 to 4 

4.80 


14 


3 

15 

10 

10 

8 

16 to 6 

17 


5 


3 


15 

13 

11 

17 

9 

17 


16 to 8 

16 


154 

| width of st_ 


20 to 12 

7 

l width of sL 

19 

i < < «« 

6 

10 


6 

6 to 4 

13 

6 

12 

20 to 8 

5 

20 to 6 

12 

12 to 4 


27 


16 

15 

20 to 6 

12.38 

16 to 10 

10.70 


10 

12 to 6 

9 

25 to 12 

4 

15 to 3 

9 

8 


* Foreign cities for comparison. 































































CITY STREETS. 


4*23 


it must actually have a considerable dip in the direction of the slope 
of the street. If steep grades are continued across intersections, 
they introduce side slopes in the streets thus crossed, which are 
troublesome, if not dangerous, to vehicles turning the corners, es¬ 
pecially the upper ones. Such intersections are especially objection¬ 
able in rainy weather. The storm water will fall to the lowest point, 
concentrating a large quantity of water at two receiving-basins, 
which with a broken grade could be divided between four or more 
basins. 



Fig. 143. ADJUSTMENT OF GRADES AT STREET- 

INTERSECTIONS. 

752. Fig. 144 shows the arrangement of intersections on steep 
grades proposed by Messrs. Rudolph Hering and Andrew Rosewater 
for the streets of Duluth, Minn. From this it will be seen that at 
these intersections the grades are flattened to three per cent for the 
width of the roadway of the intersecting streets, and that the grade of 
the curbs is flattened to eight per cent for the width of the inter¬ 
secting sidewalks. Grades of less amount on roadway or sidewalk 
are continuous. The elevation of block-corners is found by adding 
together the curb elevation at the points facing the block-corner, 
and also the sum of the widths of the two sidewalks at the corner 
multiplied by two and one half per cent, and dividing the whole by 
two. This gives an elevation equal to the average elevation of the 
curbs opposite the corner plus an average rise of two and one half 
per cent across the width of the sidewalk. 





















424 


HIGHWAY CONSTRUCTION. 


753. The instructions of the Department of Public Works of 
New York contain the following directions for regulating grades at 
street-intersections: 

“ In calculating the grades from the centre of the intersection 
to the circular corners or curb-lines, they will be established as 
follows: In the avenues when the ascents and descents of the cross 
intersecting streets exceed 1 inch in 10 feet, the grade will be cah 



culated at 1 inch in 10 feet to the curb-line from the centre, mak¬ 
ing 6 inches difference in the curbs on opposite sides of the avenues, 
and the slopes up and down the avenues will be calculated accord¬ 
ing to the grade of the avenue, let the same be more or less.” 

“ Apexes and punch-bowls to be set into the curb-line at the 
same height as the centre grade.” 

754. Accommodation summits have to be introduced between 
street-intersections, first in hilly localities to avoid excessive excava¬ 
tion, and second when the intersecting streets are level or nearly 















































CITY STREETS. 


425 


■so, for the purpose of obtaining the fall necessary for surface- 
drainage. 

The elevation and location of these summits may be calculated 
as follows: Let A be the elevation of the highest corner, B the 
elevation of the lowest corner, D the distance from corner to corner, 
and R the rate of the accommodation grade. The elevation of the 
summit is equal to 

D . R -f A + B 

■---- • 

2 

The distance from A or B is found by subtracting the elevation of 
either A or B from this quotient and dividing the result by the rate 
of grade. Or the summits may be located mechanically by specially 
prepared scales. Prepare two scales divided to correspond to the 
rate of grade—that is, if the rate of grade be one foot per hundred 
fefet, then one division of the scale should equal 100 feet on the 
map scale. These divisions may be subdivided into tenths. One 
scale should read from right to left, and one from left to right. 

To use the scales, place them on the map so that their figures 
correspond with the corner elevations; then as the scales read in 
opposite directions there is of course some point at which the op¬ 
posite readings will be the same: this point is the location of the 
summits, and the figures read off the scale its elevation. If the dif¬ 
ference in elevation of the corners is such as not to require an in¬ 
termediate summit for drainage, it will be apparent as soon as the 
scales are placed in position. 

755. Sufficient fall for surface drainage may be secured without 
the aid of accommodation summits, by arranging the grades as shown 
in Fig. 145. The curb is set level between the corners, a summit is 

CURB_LEVEL 

-BOTTOM ‘OF"GUTTER"* - 

Fig*, 1 45 ; 

SHOWING CROWN IN STREET GUTTER. 

formed in the gutter, and receiving basins are placed at the centre 
and each corner. 

756. Transverse Grade. —In transverse grade the street should 
Ije level; that is, the curbs on opposite sides should be at the same 
level, and the street crown rise equally from each side to the centre. 





4:26 


HIGHWAY CONSTRUCTION. 


But in liill-side streets this condition cannot always be fulfilled, and 
opposite sides of the street may ditfer as much as five feet; in such 
cases the engineer will have to use his discretion as to whether he 
will adopt a straight slope inclining to the lower side, thus draining 
the whole street by the lower gutter, or adopt the three-curb 
method and sod the slope of the higher side. 

In the improvement of old streets with the sides at different 
levels much difficulty will be met, especially where shade-trees have 
to be spared. In such cases recognized methods have to be aban¬ 
doned, and the engineer will have to adopt methods of overcoming 
the difficulties in accordance with the condition and necessities of 
each particular case. 

As an example of what may be done in such cases the methods 
adopted by Mr. J. T. Desmond, City Engineer of Haverhill, Mass., 
may be cited. 


In Fig. 146 is shown a street 66 feet wide, with one sidewalk 
co 



Fig. 146. 



Fig. 147. 


/ 


& 


r S1DEWALK.O 



;g\ 

^SSIDEWAUC^^. 


Fig. 148. 

ARRANGEMENT OF STREETS WITH OPPOSITE SIDES 

AT DIFFERENT LEVELS. 

5 feet higher than the other. In order to get a fair cross-section a 
third line of curbing was put in at the crest of the slope, and the 

















CITY STREETS. 


427 


slope between the two curbs sodded. This produces a very pleasing 
effect. 

In Fig. 147 the same conditions exist, but only two lines of curb¬ 
ing are used, the slope being sodded in the same manner as in the 
first case. 

Again, it often happens that two parallel streets are laid out 
with sharp descending grades, and later on the city is called upon 
to accept a new street laid out between them. The method shown 
in Fig. 148 is adopted. 

757. Transverse Contour. —The most suitable form of transverse 
contour and proper rise for each kind of pavement are given in 
Articles 618 and 619, Chapter XII. 

758. Sub-foundation Drainage of Streets. —The sub-foundation 
drainage of streets cannot be effected by transverse drains, because 
of the liability of their disturbance by the introduction of gas, 
water, and other pipes. 

Longitudinal drains must be entirely depended upon; they may 
be constructed of the same materials and in the same manner as 
road drains. The number of these longitudinal drains must depend 
upon the character of the soil: if moderately retentive, a single row 
of tiles or a hollow invert placed under the sewer in the centre of 
the street will generally be sufficient, or two rows of tiles may be 
employed, one placed at each curb-line; if the soil be exceedingly 
wet and the street very wide, four or more lines may be employed. 
These drains may be permitted to discharge into the sewers 
of the transverse streets (Fig. 149.) 





Fig. 149. 

SECTION OF SUBURBAN STREET, SHOWING BROKEN- 
STONE ROADWAY, PAVED GUTTER, TILE-DRAIN, AND 
GRAVEL WALK. 





















428 


HIGHWAY CONSTRUCTION. 


759. Surface Drainage.—The removal of water falling on the 
street surface is provided for by collecting it in the gutters, from 
which it is discharged into the sewers or other channels by means 
of catch-basins placed at all street intersections and dips in the 
street grades. 

760. Gutters.—The gutters must be of sufficient depth to retain 
all the water which reaches them and prevent its overflowing on 
the footpath. The depth should never be less than 6 inches, and 
very rarely need be more than 10 inches. 

In streets paved with granite, wood, and brick, gutters are 
formed of the same material. When the street is paved with 
asphalt the gutter may be formed either of asphalt, recoated with 
bitumen, or with granite blocks or gutter stones. The width of this 
paving need not exceed 12 inches. 

In streets where broken stone is used the gutters may be formed 
with gutter stones of granite blocks. 

761. Catch-basins are of various forms, usually circular or rectan¬ 
gular, built of brick masonry coated with a plaster of Portland 
cement. Whichever form is adopted, they should fulfil the follow¬ 
ing conditions: 

(1) The inlet and outlet to have sufficient capacity to receive 
and discharge all the water reaching the basin. 

(2) Sufficient capacity below the outlet to retain all sand and 
road detritus, and prevent it being carried into the sewer. 

(3) Trapped so as to prevent the escape of sewer-gas. (This 
requirement is frequently omitted, to the detriment of the health of 
the people.) 

(4) Constructed so that the pit may be easily cleaned out. 

(5) Inlet not easily choked by leaves or debris. 

(6) Offer the least possible obstruction to the traffic. 

(7) The pipe connecting the basin to the sewer should be easily 
freed of any obstruction. 

Figs. 150 to 153 show various forms of catch-basins. 

The bottom of the basins should be 6 or 8 feet below the street 
level, and the water level in them should be from 3 to 4 feet lower 
than the street surface, as a protection against freezing. The 
capacity and number of basins will depend upon the area of sur¬ 
face which they drain. 

In streets having level or light longitudinal grades gullies may 



CITY STREETS. 


429 


EXAMPLES OF CATCH-BASINS. 



SECTION. 



Fig. 150. PLAN. 









































430 


HIGHWAY CONSTRUCTION. 




Fig. 152. CORNER BASIN. 



Fig. 153. EARTHENWARE BASIN. 































































CITY STREETS. 


431 


be formed along the line of the gutter at such intervals as may be 
found necessary. A great variety of gully-pits and gratings have 
been introduced, and are illustrated in Mr. Baldwin Latham's ex¬ 
cellent book on Sanitary Engineering. 

762. Surface Drainage at Street Intersections. —The surface 
waters should not be carried across street intersections if it can be 
possibly avoided, but cases may arise where such has to be done. 



Fig. 153a. SEWER INLET WITHOUT BASIN. 

Where it is necessary, it can be accomplished as shown in Figs. 154 
and 155. 

Waterways formed as shown in Fig. 156 should not be con¬ 
structed: they are a nuisance, and an obstacle to traffic. 

763. Street Lines and Monuments. —In the engineering depart¬ 
ment of every city there should be adopted and carried into effect 
a system of permanent street monuments, whereby the street lines 
may be accurately relocated at any time, even a century after the 
original survey was made. In the absence of such a system, it is 











































SURFACE-DRAINAGE AT STREET INTERSECTIONS. 


432 


HIGHWAY CONSTRUCTION 


* 




T~jl M0IH9 

1 i ' 


1—T“ 

I—l— 


{-r 

SNlGSOdC 

■t—*— 

i i 




1 9NlSS0d!) 


t 


i 

i 


VfDlGQ 


D) 

a: 

:> 

o 


cr 

u 


tr> 

°S 




Fig. 156, 

OBJECTIONABLE FORM OF WATERWAY AT STREET-CROSSINGS 




























































CITY STREETS. 


433 


impossible to accurately retrace the original survey. With the im¬ 
provements continually in progress old landmarks are swept away, 
and the reproduction of former lines is largely a cut-and-try pro¬ 
cess, involving a great deal of work which is productive of only 
approximate results. 

The remedy lies in placing at all street corners substantial stone 
monuments, and protecting them by special ordinance against dis¬ 
turbance by persons excavating in the streets. 

The monuments should not be less than 4 feet long, 12 inches 
square on the bottom, and 6 inches square on the top; the top sur¬ 
face and 4 inches of each face down from the top should be ham¬ 
mer-dressed. The monuments should be set with the upper sur¬ 
face flush with the surface of the sidewalk or a few inches below, 
but so placed as to be easy of access. They should be set at a fixed 
distance from the building line—say 5 feet. If set below the level of 
the footway pavement, a hole may be cut in the pavement and closed 
with a cast-iron frame and movable cover flush with the surface of 
the pavement. (See Fig. 157.) 

The intersections of the lines can be accurately cut upon the 
top surface, or a small hole may be drilled at the intersection of the 
lines, filled with lead, and the point marked with a centre-punch. 



FIG 1 57.—SHOWING MONUMENTS AND MANNER OF 

PLACING. 

764. Monuments. —For defining the lines of country roads:. 
The monuments to be of roughly dressed stone, about 5 feet long,, 
16 inches square at the base and tapering toward the top, with the: 


























434 


HIGHWAY CONSTRUCTION. 


upper foot dressed to 8 inches square; the monument to be set in a 
pit 3 feet square and 4| feet deep; the sjiace around the stone to be 
filled with small stones, gravel, or earth, solidly packed in thin 
layers. The top of each stone marked with its diagonals, and its 
number cut on one of the faces which project above ground. 

765. Street Profiles. —The following instructions of the Dejiart- 
znent of Public Works, New York, in regard to street profiles may 
be useful. 

The drawings to be made on a horizontal scale of 40 feet and a 
vertical scale of 8 feet to the inch, and to be colored and figured as 
hereinafter indicated, with an explanatory legend. 

For streets 00 feet wide and under there will be three profiles, 
one on each side and one intermediate through the centre of the 
street, to be shown in plan and elevation. For streets more than 
00 feet wide, two additional profiles will be required, one through 
each curb- and gutter-line (to be drawn in plan only, not in 
elevation). 

The established grade-line will be shown on the elevation only. 
Vertical heights above the high-water line will be given at least 
every 50 feet for the established grade-line and for the several 
lines of profile; the former on the elevation and the latter on the 
plan. 

The plan will be drawn below the profile. 

The colors used will be as follows: 

Line of higli-water (datum) 

Vertical height-lines. 

Established grade-line. 

Natural surface as follows: 

South line of streets ) 

West line of avenues ) 

North line of streets ) 

East line of avenues ) * 

North curb of streets ) 

East curb of avenues f * 

South curb-line of streets ) 

West curb-line of avenues f 

Rock to be colored with. 

Earth “ “ . 

Flagging “ . 


Orange 

Green 

Burnt Sienna 

.Blue 

• India ink 
. Orange 
.Blue 


Blue 
.Black 
■ Red 













CITY STREETS. 


435 




Fig. 158. TYPICAL CORNER. Fig. 1 59. ROUND CORNER. 












































































436 


HIGHWAY CONSTRUCTION. 


When earth and rock occur the surveyor will be required to 
designate upon the original plan the outline of the intersection of 
the rock, when the same shall be developed by a plan parallel to 
and two feet below the established grade. 

766. Increasing the Width of the Carriageway at Street-cross- 
ings. —Experience has proven the value of the London practice of 
widening the carriageway at street-corners and the providing of 
refuges or resting-places for pedestrians. Fig. 158 shows a typical 
street-corner, and Fig. 159 shows the widened corner and refuges. 

Travel is always slower and somewhat congested at crossings, 
and the widening of the wheelway at these points expedites its 
movement; while the refuges, besides keeping the traffic on its 
proper side of the street, are of great convenience to pedestrians 
crossing the street. These refuges are usually 4 feet wide and 
about 12 feet long, and are elevated above the street surface; they 
are bordered by curb-stones, and in the centre is generally an 
ornamental lamp-post, indicating its position and carrying the street 
signs. 

Another consideration in 'favor of these corners is the oppor¬ 
tunity they present for ornamental facades, that add to the beauty 
of the city. 

767. Street Statistics. —The following table shows the length of 
streets for each of fifty of the largest cities in the United States, 
with the amount paved and unpaved, the number of miles of 
streets lined with shade-trees, extent of grassed places or parking 
along the streets, the number of miles of streets to each square 
mile of area, the percentage of street area to the area of the city, and 
the number of population to each mile of streets for the year 1890. 



CITY STREETS. 


I O ^ 

to ( 


TABLE LXXXIII. 


Cities. 

Streets. 

Miles of Stre‘ ts Lined 

with Shade Trees. 

Grassed 

Places. 

Miles of Streets to each 

square mile of Area. 

Per cent of Street Area 

to City Area. 

Number of Population 

to each mile of Streets. 

Length in miles. 

Per cent of 

Length Paved. 

Length (miles). 

Average Width 

(feet). 

Total. 

Paved. 

Graded and 
Curbed 

only. 

New York, N. Y. 

575 

358 

1 

45 

62.26 




14 30 

16.25 

2 635 31 

Chicago, Ill. 

2048 

629 

1419 

30.71 

1200 

1300 

<Tf 

l 

12.75 

15.94 

537.03 

Philadelphia, Pa. 

1151 

750 

50 

65.16 

.... • . 

, , . , 

.. 

' 8.90 

8.42 

909.61 

Brooklyn, N. Y. 

653 

375 

3 

57.43 

183 

300 

5 

24.68 

32.72 

1,234.83 

St. Louis, Mo. 

1061 

422 

40 

39.77 

50 

30 

10 

17.29 

19.65 

425.80 

Boston, Mass. 

408 

408 


100 00 




11.56 

8.76 

1 099 21 

Baltimore, Md. 

780 

459 

100 

58 85 

100 



27.48 

34.36 

556 97 

San Francisco, Cal... 

342 

92 

190 

26 90 




22.12 

28.91 

874 26 

Cincinnati, Ohio. 

486 

254 


52 26 




19.44 

18.41 

610 92 

Cleveland, Ohio. 

462 

69 

129 

14 9i 




18.57 

23.21 

565 70 

Buffalo N. Y . 

372 

194 


52 15 

200 

350 

10 

9.53 

10.47 

687 27 

New Orleans, La. 

625 

89 

261 

14.24 

25 

30 

30 

16.85 

19.15 

387.26 

Detroit. Mich . 

400 

147 


36.75 


360 

15 

19.43 

20.97 

514 69 

Milwaukee, Wis. .. . 

419 

72 

6 

17 18 

349 



24.65 

35.01 

487 99 

Washington, D. C. .. 

235 

163 


69.36 

230 

230 

20 

22.95 

43.46 

863.74 

Newark N. .T. 

186 

48 

13S 

25.81 




10 47 

11.89 

977 58 

Minneapolis, Minn.. 

800 

25 

4 

3.13 

. 

400 

4 

15.48 

23.46 

205.92 

Omaiia, Neb. 

508 

52 

41 

10.24 


10 

6 

20.73 

25.92 

276.48 

Rochester, N. Y. 

240 

72 

72 

30 00 




15.38 

14.57 

557 90 

St. Paul, Minn. 

970 

40 

325 

4.12 

50 

28 

36 

18.86 

21.44 

137.27 

Denver, Col. 

756 


756 





48.81 

13.95 

141.15 

Indianapolis, Ind.... 

400 

234 

16 

58.50 

234 

234 

6 

39.72 

56.42 

263.59 

Worcester, Mass. 

195 

195 


100.00 

150 



5.73 

5.43 

434 13 

Toledo, Ohio. 

438 

60 

220 

13.70 

70 

25 

12 

22.21 

27.76 

185.92 

New Ha.ven, Conn... 

140 

32 


22.86 




18.52 

21.04 

580.70 

T.owell, Mass . 

105 

19 

1 

18.10 

79 



9.42 

8.92 

739 96 

Nashville, Tenn. 

251 

147 


58.57 

50 

150 

20 

29 74 

28.16 

303 46 

Fall River, Ma.ss. 

106 

2 

79 

1.89 




9.68 

9.17 

101 87 

CamhrirJp'e Mass 

79 

23 


29 11 




13.55 

12.83 

886 43 

Camden, N. J. 

100 

31 

20 

31.00 

50 

1 

20 

23.04 

26.18 

583.13 

Trenton, N. J. 

100 

7 

50 

7.00 

75 

5 

5 

25.32 

GO 

574.58 

Lynn, Mass . 

125 

82 

30 

65.60 

20 



11.75 

11.13 

445.82 

Hartford, Conn. 

130 

80 

50 

61.54 

91 

91 

15 

8.77 

11.76 

409.46 

Evansville, Ind . 

136 

33 

52 

24.26 

6 

1 

12 

30.77 

40.79 

373.21 

Los Angeles, Cal_ 

800 

83 

76 

10.38 


80 

30 

28.99 

32.94 

62.99 

Lawrence, Mass.. 

82 

75 


91.46 




12.29 

11.64 

544.56 

Tlnhnk'fMi N .T 

30 

17 

3 

56 67 

9 



20.41 

22.42 

1,454 93 

Dallas, Tex. 

529 

25 

66 

4.73 

15 

15 

2 

68.88 

78.27 

71.96 

Sioux City, Iowa — 

340 

14 

75 

4.12 

45 

90 

8 

11.00 

16.67 

111.19 

Portland, Me. 

56 

- 9 

43 

16.07 

49 

3 

10 

22.31 

21.13 

650.45 

Holyoke, Ma.ss. 

50 

50 


100.00 


12 

4 

12.56 

14.28 

712.74 

Binghamton, N. Y... 

80 

4 

70 

5.00 

50 

50 

4 

7.97 

7.55 

437.56 

Duluth Minn 

224 

35 

20 

15.63 


23 

10 

69.35 

86.61: 

147.83 

Elmira, N. Y. 

90 

43 

5 

47.78 

45 

85 

6 

20.22 

21.07 

330.09 

Davenport, Iowa.... 

140 

26 

79 

18.57 

30 

5 

6 

31.75 

42.09 

191.94 

Canton, Ohio. 

150 

5 

115 

3.33 

150 

16 

8 

22. Of 

25.01 

174.59 

Taunton Ma.ss. 

200 

170 

20 

85 00 




4.22 

3.2C 

127.24 

Lacrosse, Wis. 

125 

15 

110 

12.00 

20 

20 

r* 

i 

15.2t 

19.OS 

200.72 

Newport. Kv. 

30 

27 

3 

90.00 

25 

2 


25 (K 

' 31.«E 

830.60 

Rockford, Ill. 

120 

1 31 

50 

25.83 

60 

98 

5 

18.84 

23.51 

196.53 






















































































































CHAPTER XVII. 


FOOTPATHS, CURBS, GUTTERS. 

768. A footpath or walk is simply a road under another name,, 
a road for pedestrians instead of one for horses and vehicles. The 
only difference that exists is in the degree of service required; but 
the conditions of construction that render a road well adapted to 
its object are very much the same as those required for a walk. 

The effects of heavy loads such as use carriageways are not 
felt upon footpaths, but the destructive action of water and frost is 
the same in either case, and the treatment to counteract or resist 
these elements as far as practicable and produce permanency must 
be the controlling idea in each case, and should be carried out 
upon a common principle. It is not less essential that a walk 
should be well adapted to its object than that a road should be, 
and it is annoying to find it impassable or insecure and in want of 
repair when it is needed for convenience or pleasure. In point 
of economy there is the same advantage in constructing a footway 
skilfully and durably as there is in the case of a road. 

769. Width.—The width of footwalks (exclusive of the space 
occupied by projections and shade-trees) should be ample to com¬ 
fortably accommodate the number of peojde using them. In streets 
devoted entirely to commercial purposes the clear width should be 
at least one third the width of the carriageway; in residential and 
suburban streets a very pleasing result may be obtained by making 
the walks one half the width of the roadway and devoting the 
greater part to grass and shade trees. 

The width adopted for sidewalks in several cities is given in 
Table LXXXII, page 388. 

770. Cross-slope.—The surface of footpaths must be sloped so 
that the surface-water may readily flow to the gutters. This slope 

438 


FOOTPATHS, CURBS, GUTTERS. 


439 


need not be very great; ^ inch per foot will be sufficient. A 
greater slope with a thin coating of ice upon it becomes dangerous 
to pedestrians. 

771. Foundation.—As in the case of roadways so with foot¬ 
paths, the foundation is of primary importance. Whatever material 
may be used for the surface, if the foundation is weak and yielding 
the surface will settle irregularly and become extremely objection¬ 
able, if not dangerous, to pedestrians. 

772. Surface.—The requirements of a good covering for side¬ 
walks are: 

(1) It must be smooth but not slippery. 

(2) It must absorb the minimum amount of water, so that it 
may dry rapidly after rain. 

(3) It must not be easily abraded. 

(4) It must be of a uniform quality throughout, so that it may 
wear evenly. 

(5) It must neither scale nor flake. 

(6) Its texture must be such that dust will not adhere to it. 

(7) It must be durable. 

773. Materials.—The materials used for footpaths are as fol¬ 
lows: stone natural and artificial, wood, asphalt, brick, tar con¬ 
crete, and gravel. 

774. Of the natural stones, sandstone (bluestone) and granite 
are extensively employed. 

The bluestone when well laid forms an excellent paving mate¬ 
rial. It is of compact texture, absorbs water to a very limited extent, 
and hence soon dries after rain; it has sufficient hardness to resist 
abrasion, and wears well without becoming excessively slippery. It 
can be obtained in flags of almost any size and thickness. As found 
in the quarries, the layers of stone range from 1 inch to 3 feet in 
thickness, the top beds being usually the thinner. The size of the 
blocks in superficial area varies; frequently blocks 60 feet long by 
20 feet wide and 10 inches thick are lifted from the bed. The 
largest slab as yet brought to tide-water was 20 X 24 feet and 10 
inches thick, and there are slabs used for flagging in New York 15 
by 20 feet by 8 inches. 

Granite, although exceedingly durable, wears very slippery and 
its surface has to be frequently roughened. 

775. Slabs of whatever stone must be of equal thickness 




440 


HIGHWAY CONSTRUCTION. 


throughout their entire area; the edges must be dressed true to the 
square for the whole thickness (edges must not be left feathered as 



Fig. 160. IMPROPER MANNER OF DRESSING THE 

EDGES OF CROSSING-STONES AND FLAGSTONES. 

shown in Fig. 160); and they must be solidly bedded on the foun¬ 
dation and the joints filled with cement-mortar. 

Badly set or faultily dressed flagstones are very unpleasant to 
walk over, especially in rainy weather; the unevenness causes 
pedestrians to stumble, and rocking stones squirt dirty water over 
their clothes. 

776. Specifications for Flagstones, (New York).—Flagstones 
shall be of the best quality of North Fiver bluestone, 4 feet wide, 
not less than 3 inches thick, and to contain not less than 12 super¬ 
ficial feet. The edge shall be dressed the whole depth of the stone, 
so as to lay close joints, and the top shall be cut evenly, so as to 
leave no depressions. Flagging shall be laid in four inches of sand 
or clean gritty earth, and the joints closed with cement-mortar. 

777. Wood has been largely used in the form of planks; it is 
cheap in first cost, but proves very expensive from the fact that it 
lasts but a comparatively short time and requires constant repair to 
keep it from becoming dangerous. 

778. Asphalt forms an excellent footway pavement; it is dur¬ 
able and does not wear slippery. It is largely employed for this 
purpose in Europe. 

The proportions of materials employed in Paris are given as 
follows: 

Bituminous rock. 1456 pounds 

Bitumen. 68 “ 

Sand. 784 “ 

This requires about 225 pounds of coal to heat it, and one work¬ 
man can prepare 3 tons of material in 12 hours. 

The following table gives the number of square yards that a ton 
of prepared rock-asphalt will spread: 









FOOTPATHS, CURBS, GUTTERS. 


441 


TABLE LXXXIV. 


Without Grit. 
Square yards. 

With about 

25 per cent of 
Grit. 

Square yards. 

Thickness. 

Inches. 

63 

80 

1 

51 

65 

4 

32 

40 

£ 

26 

33 

1 

16 

20 

H 

12£ 

16 

2 


A skilled workman properly assisted can lay 140 to 180 square 
yards in a day. 

779. The life of asphalt footways may be taken at about twelve 
years under ordinary traffic. The concrete will remain untouched, 
and what is left of the asphalt may be remelted, so that a renewal 
is not so costly as the first expense. 

Compressed-asphalt paths have lasted ten years in some of the 
busiest thoroughfares of London. In Leicester, uncompressed- 
asphalt paths have lasted fifteen years under considerable traffic. 

The thickness of the asphalt should not be less than one inch. 

780. Specifications for Sheet-asphalt Footway Pavements (Wash¬ 
ington, D.C.) 

Grading .—The space over which the sidewalk is to be laid will 
be graded to a depth of 3 inches below the finished surface of the 
pavement. Soft and spongy places not affording a firm foundation 
will be removed and good, clean gravel substituted therefor. The 
bed thus prepared will be thoroughly rolled and rammed to the 
satisfaction of the Engineer or his authorized representative. 

Tree-spaces .—A space of such dimensions as may be directed 
by the Engineer Commissioner (usually 2 by 4 feet) will be left 
around each tree. Around the edges of this space will be planted 
a framework of Georgia pine, 2 inches in thickness and 9 inches in 
depth. The plank forming the rear of the framework, and which 
is parallel to the curb, will be firmly nailed to the other two pieces, 
and will be cut in such a manner that it will bind underneath the 
pavement to be laid, so that the top edges will be even with the 
pavement when completed. In the spaces between the framework 
and the sides of the trench coarse sand will be placed and com¬ 
pacted by tamping with narrow rammers especially constructed for 










442 


HIGHWAY CONSTRUCTION. 


this purpose. These spaces will be then filled to the sub-grade of 
the pavement, and the tree-spaces will be filled with earth and left 
in a neat and clean condition. 

Base .—On the bed prepared as above specified a layer of clean 
broken stone, of size not exceeding f inch in largest dimen¬ 
sions, will be spread to a depth of 2f inches. This will be com¬ 
pressed by rolling and tamping to a thickness of 2 inches. On this 
will be poured, at a temperature of about 250 degrees Falir., the 
residuum of coal-tar distillation known in the trade as No. 4 Paving 
Composition. About \ gallon of this composition will be used 
for each square yard of pavement, and it will be poured on the base 
of broken stone in such manner as to thoroughly coat the stones 
on the surface and fill the interstices thereof. 

Weariny Surface .—The cementing material of the wearing 
surface will be asphalt paving-cement prepared from the best 
quality of Trinidad asphalt, obtained from the so-called Pitch or 
Asphalt Lake in the island of Trinidad, and the residuum of 
petroleum distillation, mixed in the proportions of about six parts 
of refined asphalt and one part of residuum. With this paving- 
cement will be combined the old asphalt pavement from Penn¬ 
sylvania Avenue or elsewhere, and crushed granular limestone 
quartz or other stone of a white color, in the following jwoportions: 


Old pavement. 69 to 76 per cent 

Crushed stone. 26 to 15 “ 

Asphalt cement as above specified. 5 to 9 “ 


100 100 per cent 

The old pavement will be furnished by the District at the 
property yards near the foot of New Hampshire Avenue; the other 
' materials will be furnished by the contractor. The crushed stone 
in the wearing surface will vary in size from ^ of an inch to dust. 

The asphalt pavement will be broken into pieces not exceeding 
4 inches in their largest dimensions, and will then be mixed with 
the crushed stone in the proportion of about 4 parts of asphalt 
pavement to one part of crushed stone. This mixture will then be 
heated to a temperature of about 300 degrees Falir. in a suitable 
apparatus, and thoroughly mixed and made homogeneous by 
stirring, special care being taken not to overheat the material or 






FOOTPATHS, CURBS, GUTTERS. 


443 


burn the asphalt. During the progress of mixing, asphalt cement 
will he added in the proportion of 5 per cent to 9 per cent by 
weight of the mixture; the exact proportion of asphalt cement thus 
to be added for the purpose of enriching the old pavement will be 
determined by the Engineer Commissioner. 

The material thus prepared will be brought to the work at a 
temperature of 250 degrees to 275 degrees Fahr., and will be spread 
on the base above specified by means of hot iron rakes to a thick¬ 
ness of 14 inches, and will then be compressed by rolling and ram¬ 
ming to the thickness of 1 inch. A small amount of hydraulic 
cement will then be spread over the surface, and the rolling will 
be continued until the pavement is thoroughly compressed. Care 
shall be taken at all times not to interfere with business or travel 
more than is absolutely necessary for the faithful performance of 
the work. During the time that travel is necessarily closed at any 
point the contractor shall provide temporary walks, said walk to be 
at all times in condition for pedestrians, and easy of access from 
adjoining walks. The contractor shall remove all stone, plank, 
brick, or other material of value from points where the sidewalks 
are to be laid, as the work progresses, and shall haul them to the 
nearest property yards, or otherwise dispose of them, as the Engi¬ 
neer Commissioner may desire. 

Curb .—Whenever ordered the curb will be reset. Curb will be 
redressed by the contractor whenever ordered, for which a fair 
price, to be fixed by the Engineer Commissioner, will be paid. 

781. Extracts from Specifications for Asphalt Footway Pave¬ 
ments (Paris). 

Form and Dimensions of WorJc. —Art. 7. The width of the 
sidewalks for each locality will be determined by the administra¬ 
tion, its slope by the engineer. The curb between the sidewalk 
and the roadway will not be included in this contract. 

Art. 16. The mastic pavements will be formed of a layer of 
pure asphaltic mastic at least ^ inch thick, resting on a bed of 
hydraulic concrete 4 inches thick which comprises a covering of 
hydraulic mortar at least f inch thick. 

Art. 17. The compressed-asphalt pavements will consist of an 
upper layer of compressed asphalt 1^ to inches thick, i esting on 
a foundation of hydraulic lime or cement concrete 4 to 6 inches 
thick, covered as above with mortar, or upon an old macadam road- 



444 


HIGHWAY CONSTRUCTION". 


way picked over and covered with a thin coat of hydraulic 
mortar. 

Art. 2i. The asphaltic mastic employed either for new or re¬ 
pairing oM paving shall be composed of naturally impregnated 
rock with natural bitumen of good quality, coming exclusively 
from mineral rocks. 

The fictitious bitumens extracted by the purification of the 
heavy oils or schists and by the distillation of coal, also the so- 
called fatty bitumens, and all other analogous products shall be 
rigorously proscribed. 

The rock employed after being reduced to powder will be 
melted with a sufficient quantity of purified natural bitumen to 
form a mastic which, when cold, presents a homologous mass 
slightly elastic and which does not soften under a hot sun. This 
mastic shall be moulded into blocks. There may also be used blocks 
of bituminous mastic with a base of slates manufactured by the 
process of M. Sebille. 

Art. 22. The contractor shall be bound to employ under the 
orders of the engineers upon each public way the bituminous mas¬ 
tic above described. 

The mastic shall be formed of a mixture of natural bitumen, in 
the proportion of one twelfth of its weight at most, and the calca¬ 
reous asphalt rocks of Seyssel, Seyssel-Forens, Pyrimont or Vo¬ 
lants, of Val de Travers or Lobsan, or others deemed equivalents 
by the engineers. 

The mastic having a base of slate of M. Sebille will be formed 
of a mixture of bitumen described in Art. 23 following, and of 
powdered red or blue slate of Ardennes, powdered chalk of Men- 
don or of Nanterre, and of silica from the basin of Paris, in the 
following proportions by weight: 


Retiued mineral bitumen. 

Ground slate... 


Powdered chalk. 


Silica, ground and sifted. 



100 parts 

Art. 23. The bitumen shall come as much as possible from the 
weighings of bituminous sandstone or the asphaltic rock of Maestu, 
and in their default from the dry pitch of Trinidad, perfectly puri- 








FOOTPATHS, CURBS, GUTTERS. 


445 


fied. It ought to be viscid at the ordinary temperature, never 
brittle or liquid; drawn into threads it should lengthen and only 
break in very fine points. 

Art. 24. The rock employed should he calcareous, soft, with 
fine grain, texture fairly compact, regularly impregnated with 
bitumen so as not to show black and white spots; it should be of a 
brown color; heated to 122 to 140 degrees Fahr. it should soften 
and break on being torn. Care must be taken for the area in 
asphalt to choose only such pieces as are of the most even grain 
and richest impregnation. The rock of Lobsan, however, should 
not be employed alone in the asphalt roadways; it ought to be 
mixed with other rocks less fat, in proportions which will be de¬ 
termined by the engineer according to the composition of the 
other rocks. It should contain at least 7 per cent of bitumen and 
at the most 93 per cent of lime; its change into mastic must not 
require more than 9 per cent of bitumen. 

Art. 25. The materials entering into the composition of the 
pavements are the mastics described in Art. 22; pure gravel grit 
and natural bitumen to assist the melting. These materials ought 
to be generally employed in the following proportions by weight: 


( Asphaltic mastic. 100 

Foot-pavements with a base of asphalt \ Bitumen. 6 

t Grit. 60 

C Asphaltic mastic. 100 

Foot-pavements with a base of slate.... \ Bitumen. 7 

t Gravel. 50 


Art. 26. One month before the award of this contract the 
competitors must deposit at the office of the works in Paris samples 
of, 1st, a block of the mastic described above; 2d, specimens 
of the asphaltic rocks and the natural bitumens they intend to 
use; 3d, a note indicating the elements of the composition of 
the mastics, and proportions of the various rocks that they intend 
to employ in the composition of the asphaltic areas. 4 he blocks 
and specimens of rocks and bitumen to have the trade-marks of 
the works from whence they came and the signatures of the com¬ 
petitors. 

The necessary certificates to compete for the contract will not 
be delivered till after the examination and acceptance by the 
engineers of the specimens deposited. During all the term of this 










446 


HIGHWAY CONSTRUCTION. 


contract the contractor can only use materials exactly similar to 
the specimens deposited. 

Art. 27 provides for continuous inspection of the contractor’s 
works, and the right to compel the contractor to manufacture the 
mastics in the depots belonging to the city. 

Art. 31. The lime employed is to be hydraulic lime in powder. 
It must be brought onto the works in sealed bags marked with the 
name of the maker. Only the lime and cement designated in the 
specifications for the construction and repair of sewers will be 
allowed. 

Art. 32. The broken flint must pass through a ring of 2 J inches 
and be at least f inch thick. It must be free from all earthy 
matters and washed clean. 

Art. 33. The sand shall be dredged from the Seine and well 
cleansed from all foreign matter; it shall be screened from all 
grains larger than -§ inch for the mortars or T 3 ^ inch for grit for 
the mastic pavements. The grit for this last purpose shall be 
perfectly washed and dried before use. 

Art. 34. The mortar of hydraulic lime shall be composed of 5 
parts of sand and 2 parts of lime, by volume, furnished in powder; 
the mixture shall be directly reduced to a paste by adding the 
quantity of water exactly required to reduce it to the consistency 
of plastic clay. 

The cement-mortar shall be composed of 1 part of hydraulic 
cement of Bourgogne or Portland cement of Boulogne and 3 parts 
of sand; the sand and cement shall be thoroughly mixed before 
the addition of any water. All mortar which shall have set shall 
be rejected. 

Art. 35. The beton shall be composed ordinarily of 2 parts in 
volume of mortar and 3 of stone. The mixture, made either by 
rake or cylinder, must be perfectly uniform. 

All beton not used at the time of making shall be rejected. 

Art. 36. The bed of beton for the foundation of the sidewalks 
shall be well rammed and compressed, and must at least commence 
to set and dry before receiving mastic or asphalt. The beton 
shall in addition be covered with a layer of mortar | inch thick. 

The gravel for foundation shall pass in every direction through 
a ring 2 inches in diameter. It must be perfectly compressed and 
sprinkled with lime-grout. This foundation shall have commenced 



FOOTPATHS, CURBS, GUTTERS. 


447 


to set before the application of the mastic, and shall be covered 
with a layer of mortar like the beton. 

Art. 39. The ground upon which the mastic pavement is to be 
placed shall always be previously rammed, watered, and crowned 
with care. When it is thus made solid the contractor shall spread 
over it the foundation layer, formed according to the orders of the 
engineer—either a bed of beton or of sand covered by a layer of 
mortar, or a bed of sand impregnated with goudron 2f inches thick, 
or any other foundation prescribed by the engineer. 

In all cases the pavement shall not be laid till the foundation 
has attained the firmness desired and becomes quite dry. 

The contractor must conform to the following orders for the 
manufacture of the mastic to be used for pavements: 

The mastic shall be prepared and cast in one or more manufac¬ 
tories belonging to the contractor, and which shall always remain 
open to the inspection of the engineers and their agents. 

The contractor shall besides establish in the manufacturing 
depots, both of asphalt and mastic, offices exclusively for the 
agents of the administration set apart for the inspection of the 
composition of these materials. These materials shall not be 
admitted into the works without a carter’s delivery note given by 
the inspector, setting forth that they have been manufactured in 
accordance with the specifications. 

There shall only be allowed in the works blocks of mastic con¬ 
forming to the samples deposited and accepted before the award, 
and bearing the trade-mark, or the old mastics from the walks 
and streets of Paris. All other bituminous matters, resinous or 
fatty, found in the works by the agents of the administration will 
subject the contractor to a deduction of $100 for each time they are 
found. 

To assure the execution of these conditions the contractor must 
not have in any manufactory, under the same penalty, any other 
blocks than those which should be prepared in his works, and the 
old mastics that have been taken up. 

The use of the old mastic is authorized in the works of the city 
in the proportion of one half with the new; the pieces of the old 
sidewalks having been perfectly cleaned with great care, and re¬ 
generated by the addition of new purified bitumen and a sufficient 




448 


HIGHWAY CONSTRUCTION". 


quantity of powered asphalt to render the old mastic, when melted, 
of the aspect and consistence of the blocks in fusion. 

This mastic shall be melted in hermetically closed boilers, on 
wheels of a model approved by the administration, and arranged so 
that the material can be conveyed from the factory to the place to 
be used, ready to be employed. 

For melting, the mastic is broken into pieces 4 inches cube, 
then the bitumen is melted and the mastic added little by little. 

The grit must not be thrown into the boiler til] the mastic is 
completely dissolved. 

During the whole time of the operation the matter must be 
stirred up almost constantly, so that the combination shall be well 
made and the mastic not burned. 

The mastic being well melted and perfectly homogeneous, it 
shall be run out in bands of about five feet wide, spread with a 
wooden float, and levelled with a strike, so as to present neither 
fissure nor joint. The mastic must be perfectly level, and matched 
exactly with the curbs, etc., against which it is laid. For this pur¬ 
pose the parts of the curbs, flags, etc., which will be in contact with 
the bitumen shall be previously warmed and goudroned. 

Art. 40. Upon the soil, well shaped and rammed, shall be 
placed a bed of concrete, covered with a layer of mortar. 

The asphaltic rock, conforming to article 24, broken down or de¬ 
crepitated by heat, shall be raised to a uniform temperature of from 
248 to 266 degrees Fahr., and carried to the place of employment in 
vehicles that will prevent as much as possible the loss of heat. It 
must be completely freed from the the water it contains. The use 
of old compressed asphalt, taken from old roads, is authorized for 
mixture with new asphalt, in the proportion of one quarter of old com¬ 
pressed to three quarters of new rock, provided that the old shall be 
cleansed with great care before grinding and mixing with the new. 

Asphalt shall not be put on the concrete foundation until it is 
perfectly set and dry. 

The powder shall be spread with a thickness about two fifths 
more than the finished thickness, levelled with great care, and then 
rammed, at first carefully, then gradually augmenting the force by 
means of cast-iron pilous heated to the proper temperature in 
portable furnaces. In specially exceptional cases the compression 





FOOTPATHS, CURBS, GUTTERS. 


449 


may also, with the written permission of the engineer, be accom¬ 
plished by means of rollers. 

In every case, after the pilonnage is finished, the surface shall 
be smoothed by means of a heated iron (Ussoir). 

The road shall not be open to traffic until it is quite cool. 

Art. 43. In conformity with the contract price, stipulated here¬ 
after, diminished by the rebate of the awarded contract, the con¬ 
tractor must make the necessary repairs to all asphaltic mastic foot¬ 
paths and areas, furnishing the necessary labor and materials, so that 
they shall be kept in proper condition. He must each year of the 
duration of the contract completely relay, in new material, at least 
the fifteenth part of the surfaces of mastic and compressed asphalt. 
The surfaces in mastic must he properly plane and regular, pre¬ 
senting neither hollows nor projections of more than § inch in a 
circle whose radius is 3^ feet. These surfaces must be free from 
fissures. 

Art. 45. As the works in asphalt or mastic are accepted by the 
engineer they will pass into the charge of the contractor, who will 
receive for the maintenance the price stipulated, commencing 
from the first of January next following their acceptance, what¬ 
ever may be the date of said acceptance. 

In the last nine months of the year instalments may be paid on 
the contract when the engineers recognize that the conditions have 
been loyally carried out. The accumulated sums of these instal¬ 
ments must not exceed four fifths of the amount of the sums which 
shall be due after the time has expired. The balance of the con¬ 
tract price of the year will he paid in the course of the first quarter 
of the following year. 

Art. 49. All damages in the bituminous surface, such as fissures 
or cracks of at least T V inch in width, or parting from the curbs T 3 g- 
inch in width, any lifting up or breaking away of the mastic for at 
least yV inch in depth, depressions in consequence of settlement of 
at least | inch in depth under a straight-edge, 3£ feet long, will 
subject the contractor to a deduction of 3 francs (58 cents) per day 
when the repairs shall not have been done within 48 hours after- 
notice given by the engineer. 

Art. 51. During the continuance of irost, and during the first; 
month after the commencement of the thaw, there shall be no re¬ 
pairs to the pavements maintained by the contractor, and the in- 



450 


HIGHWAY CONSTRUCTION. 


spection for defects shall be suspended; but the contractor shall fill 
with sand and gravel any holes in these pavements within 24 hours 
after notification by the engineer, under a penalty of 10 francs 
($1.93) for each day they remain unfilled. He may be authorized, 
in exceptional cases, to fill the holes with broken flint or melted 
bitumen, but must replace the flint or bitumen with asjihalt as soon 
as the weather permits. It must be so arranged that the main re¬ 
pairs, intended to re-establish the normal outline of the roadways, 
are effected from May 1st to November 1st. 

Art. 65. When a workman leaves one of the districts of the 
works under the municipal service, he must have a certificate from 
the contractor showing the cause for which he left. 

This certificate shall be submitted at once to the engineer, who 
shall be at liberty to refuse the right of employing the said work¬ 
man, without the contractor deriving therefrom any excuse for 
not furnishing, when requisite, the number of workmen required. 
In default of a certificate, the workman cannot be admitted, except 
on the written order of the engineer. 

782. Compressed-asphalt Tile-pavement. —The success attend¬ 
ing the introduction of compressed-asphalt blocks for light-traffic 
streets has led to the use of the same composition under the name 
of “ compressed-asphalt tiles ” for sidewalk pavements. These 
tiles can be made of any form and thickness required. The dimen¬ 
sions found most suitable are 8x8 inches square and 2| inches thick. 
In this form they have been laid in large quantities during the last 
.seven years and appear to have given satisfaction. 

782. Specifications for Laying Compressed-asphalt-tile Sidewalk- 
pavements. 

(1) The tiles will be laid on a foundation of gravel and sand 
thoroughly compacted by ramming and rolling. 

(2) The space over which the pavement is to be laid shall be ex¬ 
cavated to the depth of ten (10) inches below the top surface of the 
finished pavement. Any perishable or other objectionable material 
found below this depth must be removed and the space filled with 
clean gravel or sand; the surface of the foundation so prepared shall 
be thoroughly compacted by ramming and rolling. 

(3) The foundation for the tiles will be formed of a bed of fine 
bank gravel four inches in depth when compacted, screened from 
all pebbles measuring more than one and one-half inches. Upon 




FOOTPATHS, CURBS, GUTTERS. 


451 


the gravel there shall be laid a bed of fine, sharp sand, washed and 
dried, four inches in thickness. The foundation of sand and gravel 
shall then he thoroughly consolidated by ramming and rolling, care 
being taken to preserve the surface of the sand parallel to the slope 
required for the finished surface of the pavement. (The hand- 
rammers shall weigh not less than 25 lbs., and the rollers not less 
han 300 lbs.) 

(4) The tiles shall be laid at right angles to the street line, and 
their surface when finished must be even with the top of the curb 
and shall have the required slope. 

The tiles shall be laid by the pavers standing or kneeling upon 
the tiles already laid, and not upon the sand-bed. 

Each course of tiles must be of uniform width and depth, and 
so laid that all longitudinal joints shall be broken by a lap of at 
least two inches. 

Each course shall be driven against the course preceding it by 
a maul so as to make tight joints. 

When thus laid the tiles will be covered with clean, fine, dry 
sand, free from loam or earthy matter, and screened through a 
sieve having not less than 20 meshes to the inch. 

(5) The tiles shall then be carefully rammed by placing a plank 
over several courses and striking the plank with a rammer weigh¬ 
ing not less than 25 lbs. 

The ramming shall be continued until the tiles reach a firm, un¬ 
yielding bed and present a uniform surface with the required 
grade. Any lack of uniformity in the surface must be corrected by 
taking up the tiles and relaying them. 

When the ramming is completed a thin layer of fine dry sand 
shall be spread over the surface and swept into the joints. 

784. Brick. —Brick of suitable quality well and carefully laid 
on a concrete foundation makes an excellent footivay pavement 
for residential and suburban streets of large cities, and also for the 
main streets of the smaller towns. The bricks should be a good 
quality of paving-brick (ordinary building-brick are unsuitable; 
they soon wear out and are easily broken). The bricks should be 
laid in parallel rows on their edges, with their length at right 
angles to the axis of the path. They should be set in cement- 
mortar and the joints filled flush and made as close as possible. 



452 


HIGHWAY CONSTRUCTION. 


785. Specifications for Brick Walks (Washington, D. C.).— 

Brick pavements will be laid on a foundation of gravel and sand;, 
and the bricks will be furnished by the District, delivered on the 
line of the work. The space over which the pavement is to be 
laid will be excavated to the depth of 10 inches below the top 
surface of the proposed pavement when thoroughly compacted by 
rolling or ramming. Any objectionable or unsuitable material 
below the bed will be removed, and the space filled with clean 
gravel or sand. Care must be taken in excavating to preserve the 
proper slope parallel with the surface. Upon the foundation will 
be laid a bed of fine sandy bank gravel, 4 inches in depth when 
compacted, screened from all pebbles measuring more than 11- 
inches in their largest dimensions, and thoroughly rolled or 
rammed. Upon this will be laid a bed of fine, clean, sharp sand, 
4 inches in thickness, to serve as a bed for the bricks, which will 
be laid directly upon and imbedded in it with close joints. Special 
care will be observed to make the surface of this bed of sand 
parallel to the surface of the pavement when finished. The bricks 
must be laid by the pavers standing or kneeling upon the bricks 
already laid, and not upon the bed of sand. 

The bricks are to be laid at right angles with the line of the 
street, or in herring-bone style, as may be directed by the Engineer 
Commissioner, and even with the top of the curb w T hen rammed; 
each course to be of bricks of a uniform width and depth, and so 
laid that all longitudinal joints shall be broken by a lap of at least 
2 inches. When thus laid the bricks will be immediately covered 
with clean, fine, dry sand, free from loam or earthy matter, and 
screened through a sieve or screen having not less than 20 meshes 
to the inch. The bricks will then be carefully rammed by placing 
a plank over several courses and ramming the plank with a heavy 
hammer. The ramming will be continued until the bricks reach a 
firm, unyielding bed and present a uniform surface, with proper 
grade and slope. Any lack of uniformity in the surface must be cor¬ 
rected by taking up and relaying. When the ramming is complete 
a sufficient amount of fine, dry sand, as above described, will be 
spread over the surface and swept or raked into the joints. 

Rectangular spaces, 7 by 3 feet in dimensions, will be left 
unpaved around trees where already planted, and at intervals of 
25 feet between centres adjacent to the curb on streets where 




FOOTPATHS, CURBS, GUTTERS. 


453 


trees have not been planted. When so ordered a continuous tree 
-space of 4 feet wide will be left unpaved adjacent to the curb. 
Edges of brick pavements when not abutting against the curb 
will be finished with a continuous row of brick on edge. 

Quality of Brick .—Sidewalk paving-brick to be of dimensions 

by 4 by inches, bard-burned throughout, of dark red color, 
without flaws or cracks, and square and true on the edges. 
Specimens required. 

Arch-bricks to be of dimensions 8^ by 4, by 2£ inches, hard- 
burned throughout, sound, and of true and regular shape. All to 
conform to the samples submitted with the proposals. No swelled 
brick or soft or salmon brick will be allowed. Specimens required. 

In relaying brick sidewalks the existing sidewalks will be taken 
up and the bricks carefully piled and preserved. The bed will then 
be prepared in the same manner as prescribed for new brick walks. 
After the bed is prepared the old brick will be cleaned of all adher¬ 
ing materials so that they can be relaid with close joints, when they 
will be laid as prescribed for new brick pavements. 

786. Artificial Stone.—Artificial stone is being extensively used 
as a footway-paving material both in Europe and America. Its 
manufacture is the subject of several patents, and numerous kinds 
are to be had in the market. When manufactured of first-class 
materials and laid in a substantial manner, with proper provision 
against the action of frost, artificial stone forms a durable, agreeable, 
and inexpensive pavement. 

The varieties most extensively used in the United States are 
known by the names of “ granolithic,” “ monolithic,” “ ferrolithic,” 
“ kosmocrete,” “ metalithic,” etc. 

The process of manufacture is practically the same for all kinds, 
the difference being in the materials employed; the usual ingredi¬ 
ents are Portland cement, sand, gravel, and crushed stone. 

787. Artificial stone-for footway pavements is formed in two 
ways, viz., in blocks manufactured at a factory and brought on the 
ground and laid in the same manner as natural stone, or the raw 
materials are brought upon the work, prepared and laid in place, 
blocks being formed by the use of board moulds. 

788. The manner of laying is practically the same for all kinds. 
The area to be paved is excavated to a minimum depth of 8 inches, 
and to such greater depths as the nature of the ground may require 



454 


HIGHWAY CONSTRUCTION. 


to secure a solid foundation. The surface of the ground so exposed 
is well compacted by ramming, and a layer of gravel, ashes, clinker, 
or other suitable material is spread and consolidated; on this is 
placed the concrete wearing surface, usually 4 inches thick. As a 
protection against the lifting effects of frost the concrete is laid in 
squares, rectangles, or other forms having areas ranging from 6 to 
30 square feet, strips of wood being employed to form moulds in 
which the concrete is placed. After the concrete is set these 
strips are removed, leaving joints about half an inch wide between 
the blocks. Under some patents these joints are filled with cement, 
under others with tarred paper, and in some cases they are left open. 

789. Good artificial stone is far superior to any other material 
for footway pavements. It is of a uniform temper and homoge¬ 
neous throughout, and consequently its wear is more uniform than 
that of natural stones. It is practically non-absorbent, and conse¬ 
quently dries very quickly after rain. 

790. The quality of the cement is an important point in the 
manufacture of artificial stone. A cement of improper quality will 
cause cracking. The characteristics of good cement are treated of 
in Chapter IX. 

New Portland cement when spread and subjected to a process of 
aeration will increase in bulk at least 5 per cent. If stones are 
manufactured with such cement they will blow and crack. Cement 
increases in strength with age, and therefore stone manufactured 
with it will also increase in the same ratio; and again, Dykerhoff 
has shown that slow-setting cement had an average expansive power 
of .0734 per cent, and quick-setting .2019 per cent, over a period of 
twelve months. 

791. The following detailed particulars for the laying of con¬ 
crete footway pavements is taken from “ Eoads, Streets, and Pave¬ 
ments,” by Q. A. Gillmore: 

“ Concrete footpaths should be laid upon a form of well-com¬ 
pacted sand, or fine gravel, or a mixture of sand, gravel, and loam. 
The natural soil, if sufficiently porous to provide thorough sub¬ 
drainage, will answer. 

“ It is not usual to attempt to guard entirely against the lifting 
effects of frost, but to provide for it by laying the concrete in 
squares or rectangles, each containing from 12 to 1G superficial 
feet, which will yield to upheaval individually like flagging stones. 



FOOTPATHS, CURBS, GUTTERS. 



without breaking and without producing extensive disturbance in 
the general surface. 

“ When a case arises, however, where it is deemed necessary to 
prevent any movement whatever, it can be done by underlaying the 
pavement with a bed of broken stone, or a mixture of broken stone 
and gravel, or with ordinary pit-gravel containing just enough of 
detritus and loam to bind it together. In high latitudes this bed 
should be 1 foot and upwards in thickness, and should be so 
thoroughly subdrained that it will always be free from standing 
water. It is formed in the usual manner of making broken-stone 
or gravel roads already described, and finished off on top with a 
layer of sand or fine gravel, about one inch in depth, for the con¬ 
crete to rest upon. 

“ The concrete should not be less than 34 and need rarelv ex- 
ceed 4 to 4\ inches in thickness. The upper surface to the depth of 
4 inch should be composed of hydraulic cement and sand only. 
Portland cement is best for this top layer. For the rest, any 
natural American cement of standard quality will answer. The 
following proportions are recommended for this bottom layer: 


Rosendale or other American cement.1 measure 

Clean, sharp sand. 

Stone and gravel.5 


“ It is mixed from time to time as required for use, and is com¬ 
pacted with an iron-shod rammer in a single layer to a thickness 
less by \ inch than that of the required pavement. As soon as this 
is done and before the cement has had time to set, the surface is 
roughened by scratching, and the top layer, composed of 1 volume 
of Portland cement and 2 to 2^ volumes of clean, fine sand, is 
spread over it to a uniform thickness of about 1|- inches and then 
compacted by rather light blows with an iron-shod rammer. By 
this means its thickness is diminished to | an inch. It is then 
smoothed off and polished with a mason's trowel and covered up 
with hay, grass, or other suitable material to protect it from the 
rays of the sun and prevent its drying too rapidly. 

«It should be kept damp and thus protected for at least ten 
days, and longer if circumstances will permit; and even after it is 
open for travel a layer of damp sand should be kept upon it for 
two or three weeks, to prevent wear while tender. 






456 


HIGHWAY CONSTRUCTION. 


“ At the end of one month from the date of laying, the Port- 
land-cement mixture forming the top surface will have attained 
nearly one half its ultimate strength and hardness, and may then 
be subjected to use by foot-passengers without injury. 

“ The rammers for compacting the concrete should weigh from 15 
to 20 pounds, those used on the surface layer from 10 to 12 pounds. 
They are made by attaching rectangular blocks of hard wood shod 
with iron to wood handles about three feet long, and are plied in 
an upright position. Certain precautions are necessary in mixing 
and ramming the materials in order to secure the best results. 
Especial care should be taken to avoid the use of too much water 
in the manipulation. The mass of concrete, when ready for use, 
should appear quite incoherent and not wet and plastic, contain¬ 
ing water, however, in such quantities that a thorough ramming 
with repeated though not hard blows will produce a thin film of 
moisture upon the surface under the rammer, without causing in 
the mass a gelatinous or quicksand motion.” 

792. One cubic yard of concrete laid 3 inches thick will cover 
10 square yards of surface. For the Avearing surface the cement 
and sand are mixed in equal parts. 

793. Covering Capacity of Cement in Square Feet. 

Thickness in Inches. 


1" f" 

1 bbl. of Portland cement will cover. 36 48 72 

1 bbl. cement and 1 bbl. sand will cover. 66 84 132 

1 bbl. cement and 2 bbls. sand will cover. 96 124 192 


794. Wear. —As regards the wear of artificial stones, the follow¬ 
ing notes from London may be interesting: “ Artificial stones have 
now been used by almost every Vestry and District Board in the 
metropolis, and from testimonials it would appear that they have 
given satisfaction.” 

A portion of Victoria stone was laid in Piccadilly in 1872, and 
is said to be in good condition still, having been in use nineteen 
years. 

In 1869 the approach to Blackfriars Bridge was paved with 
Victoria stone, and six years later, Mr. Carr, the engineer, said, the 
surface was perfect and the wear decidedly less than York stone 
contiguous. This stone has also been laid in Holburn, where the 






FOOTPATHS, CURBS, GUTTERS. 


457 


traffic is estimated at 88,355 persons daily, and Aldgate High Street, 
where the traffic is estimated at 79,048 daily. Portions of the stone 
were taken up after five years, and the wear was found to be so 
slight as to be scarcely measurable. 

Imperial stone has also been largely used throughout the 
metropolis, and appears to have given every satisfaction. 

Several varieties of good stone are in the market; as examples 
the following may be cited: 



Cost per 
yard laid. 

Tensile Strain 
in pounds per 
square inch. 

Compressive 
Strain, Jbs. per 
square inch. 

Thickness 

in 

inches. 

Weight in 
lbs. per 
cubic ft. 

Imperial.. 

$1.35 

980 

9.492 

2 t \ 


Croft . 

1.32 


9,394 

2 

132 

Victoria .. 

1.38-1.44 

1,125 

8,321 

2 

144 

Granolithic. 

1.31 

1,000 

8,500 

2 


Jones annealed.... 

1.30 

510* 

l,500f 

24 

150 

York (natural). 

1.56 

5,714 

3 

156 


* 1 month old. f 12 months old. 


The following tests were made by Mr. W. Sykes, Surveyor, 
Pulham, London, to find the comparative wear of artificial and 
natural stones. The stones were of equal superficial area, all bound 
together with cord, so that each stone found its own bed when 
rubbed on York stone with sand and water. 



York. 

Imperial. 

Victoria. 

Croft. 

Thickness before being rubbed.. 
First hour... 

24 in. 

2st 

2fV 

2 A 

44 

2qf ia. 
2/t 

2rV 

9 6 

3 

¥8" 

2A ia. 
2^? 

2qV 

2 

3 

¥8 

2*V in - 

2t8 

2 

133 

1 2 ¥ 

3 

¥8" 

Second hour. 

Third hour. 

Total wear. 



From these figures it will be seen that the total wear in the 
three hours was for York 44 of an inch, Imperial j 3 ¥ , Victoria ¥ 3 ¥ , 
Croft ¥ 3 ¥ . 

This experiment is interesting as showing that the wear of 
York was ¥ inch more than that of artificial stone; also that the 







































458 


HIGHWAY CONSTRUCTION". 


Imperial, Victoria, and Croft wore equally, and would therefore be" 
of the same degree of hardness. 

The York stone referred to above is a sandstone composed 
chiefly of silica cemented together by a matrix of lime, clay, etc.; 
it is of very unequal quality, being either exceedingly hard or quite 
soft; it is also very absorptive, and is liable to laminate under 
f i ost. 

795. Specifications for Concrete Footwalks.— Preparation of 
Foundation .—The natural-soil surface shall be regulated and 
graded to a depth of 8 inches below the level of the finished sur¬ 
face of the walk; perishable and objectionable material shall be re¬ 
moved. On the surface so graded spread a layer of clean gravel 
(broken bricks or steam ashes) to such depth as will give on 
thorough consolidation a thickness of 4 inches. On the foundation 
so prepared the concrete shall be placed; moulds formed of ^-inch 
boards shall be placed at every 6 feet and adjusted to the required 
grade and pitch. The concrete shall be placed in these moulds and 
thoroughly rammed. After the concrete has set, its surface will be 
covered with the wearing coat, one inch thick, the surface of which 
shall be neatly trowelled to the required grade. 

Traffic shall be kept off for a period of 15 days or until the 
surface is thoroughly set. 

All vault-covers, stop-cock boxes, etc., shall be adjusted to the 
required grade, and the concrete shall make neat and close connec¬ 
tion with their surface. 


The concrete shall be composed of: 

American hydraulic cement.1 part 

Broken stone.7 parts 

Gravel and sand. 3 “ 

The wearing surface will be composed of: 

Portland cement. 1 part 

Sharp sand .1 “ 


796. Specifications for Artificial-stone Footpaths (Washington, 
D. C.).—The contractor shall remove all stone, plank, bricks, or 
other materials of value from points where the sidewalk is to be 
laid as the work progresses, and shall haul them to the nearest 
property yard, or otherwise dispose of them as the Engineer Comis- 








FOOTPATHS, CURBS, GUTTERS. 


459 


sioner may direct. Care shall be taken at all times not to interfere 
with business or travel more than is absolutely necessary for the 
faithful performance of the work. No more than 100 feet shall be 
closed to travel at any one time, nor remain closed for a longer time 
than three days, and free ingress and egress from the streets to all 
stores and hallways shall be provided for at all times; and during 
the time that travel is closed at any point the contractor shall pro¬ 
vide a temporary walk, said walk to be at all times in condition, 
perfectly safe for pedestrians, and easy of access from adjoining 
walks. 

The contractor shall make such cutting and tilling as may be 
necessary to bring the foundation to the subgrade, 6 inches below 
the established grade of the sidewalk. 

Whenever the Engineer Commissioner or inspector may deem 
it necessary, the foundation shall be consolidated by wetting, rolling, 
or ramming, to give it proper stability. Upon the foundation thus 
prepared there shall first be laid 3 inches of concrete, composed of 
one part natural hydraulic cement, two and one half parts sand, and 
five parts broken stone, which shall be rammed in place to the satis¬ 
faction of the Engineer Commissioner. On this concrete bed shall 
be laid three quarters of an inch of mortar, composed of four 
measures of clean, sharp sand and one of Portland cement, which 
shall be put in dry as possible, and rammed in place with an iron 
rammer weighing at least 25 pounds. Upon the foundation thus 
prepared shall be laid square blocks or tiles 2f inches thick, measur¬ 
ing 18 inches on a side. They shall be laid so as to present a true 
surface on top and conform to the exact grade of the sidewalk. A 
thin grouting of pure Portland cement of the best quality shall be 
spread over the surface and carefully swept into the joints. All 
superfluous grouting shall be cleaned off, and the walk shall be 
protected with plank or otherwise until the cement has thoroughly 
set. 

Driveways crossing the footpath shall be laid with granite or 
asphalt blocks, as may be directed by the Engineer Commissioner. 
The tiles shall be 2J inches thick. The lower If inches to be com¬ 
posed of one part Portland cement (equal to that specified in 
current District of Columbia specifications) and two parts of clean, 
sharp sand, thoroughly mixed, using as small a quantity of water 
as possible, and carefully rammed into the moulds. The upper 




4G0 


HIGHWAY COHSTRUCTIOH. 


one-lialf inch and the sides for one-half inch shall be composed 
of one part Portland cement, of same quality as above, and one part 
clean, sharp sand. 

The surface shall be finished smooth but not polished. The 
tiles, when being seasoned, shall be kept wet for the first five days. 
No tiles shall be used on the work unless guaranteed by the con¬ 
tractor to be at least thirty days old. Unless otherwise ordered, the 
edge of the sidewalk shall be finished with plastering of Portland 
cement and sand of equal parts. The blocks will be laid with the 
edges perpendicular to or parallel with the line of the street, as may 
be ordered by the Engineer Commissioner. 

Cement Inspection .—No cement shall be used on this work 
unless approved by the Engineer Commissioner. For this purpose 
he shall be entitled to take one-lialf pound from each package. 
The decision of the Engineer Commissioner shall be final in all 
cases, and no cement condemned by him shall be used on the work 
for any purpose whatever. All cements will be required to pass the 
tests specified in current District of Columbia specifications. 

All surplus material and refuse shall be removed by the con¬ 
tractor twenty-four hours after the completion of the work' and in 
case of neglect on the part of the contractor to do so within the speci¬ 
fied time, the Engineer Commissioner shall have the same removed, 
and the expense thereof shall be charged to the contractor and 
deducted from his estimates. Whenever any private driveway 
crosses the sidewalk, the plan thereof shall be modified as the 
Engineer Commissioner shall direct. 

No material of any kind shall be used until it has been examined 
and approved by the Engineer Commissioner, who shall have full 
power to condemn the work or material not in accordance with the 
specifications, and to require the contractor to remove any work or 
material so condemned, and at his own expense to replace the said 
work or material to the satisfaction of the Engineer Commissioner. 
In case the contractor shall neglect or refuse, after written notice, 
to remove or replace said rejected work or material, it shall be 
removed and replaced, by order of the Engineer Commissioner, at 
the contractor’s expense. 

The work is to be commenced and carried on at such times and 
places and in such manner as the Engineer Commissioner shall 
direct. 



FOOTPATHS, CURBS, GUTTERS. 


461 


The contractor will not be allowed to obstruct private drive¬ 
ways or approaches or to dig up or occupy the street by material 
more than is absolutely necessary for the prosecution of the work, 
special care being taken to inconvenience the public as little as 
possible. 

When the construction of any piece of work is begun it shall be 
fully completed before the force is removed. In case this is not 
done, the Engineer Commissioner shall have the work done, and 
the expense thereof shall be charged to the contractor and deducted 
from his estimates. 

If any overseer or workman employed, by the contractor shall be 
declared by the Engineer Commissioner to be unfaithful or incom¬ 
petent, or shall refuse to obey the instructions of the inspector, the 
contractor shall forthwith dismiss such person and not again employ 
him on any part of the work. The contractor will be held respon¬ 
sible for all injury done to the work in any way until it is accepted 
and measured by the engineer. 

Measurement of Work .—All artificial stone-block walks, includ¬ 
ing stone and mortar foundation, will be paid for by the square 
yard of finished surface, in accordance with the schedule in printed 
form of bid, except when it is fitted around poles, lamp-posts, or 
scuttle-holes, in which case these spaces will not be deducted. Tree- 
spaces will not be deducted. 

Curb .—Whenever ordered the curb will be reset. Curb will be 
redressed by the contractor whenever ordered, for which actual cost 
plus 15 per cent will be paid. 

Tree-spaces. —Tree-spaces shall be left wherever necessary. 
These spaces shall be outlined by boards of sound Georgia pine, 2 
inches thick and 9 inches wide, set on edge, with their top edge 
even with the pavement when completed. The plank forming the 
* rear of this framework and which is parallel with the curb shall be 
firmlv nailed to the other two pieces, and shall be cut in such manner 
that it will bind underneath the pavement when completed. The 
blocks shall be laid as closely to the boards as possible, and all corners 
and vacant spaces shall be filled with mortar similar in composition 
to that of which the blocks are made. 

796a. Kosmocrete.—The artificial stone known by this name 
is extensively used in Brooklyn, N. T.; it is formed as follows: 
A bottom course of dry cinders, about 12 inches thick, is laid. 



462 


HIGHWAY CONSTRUCTION. 


and upon this a layer of concrete about 4 inches thick, composed 
of 3 parts of granulated granite or gravel, 4 parts of one and 
one-half inch stone, and 1 part of Portland cement. On this con¬ 
crete is worked a facing about one inch thick, composed of granu¬ 
lated granite, a small percentage of silicious grit, Portland cement, 
and carbon. The purpose of the granite and grit is to prevent the 
surface from becoming slippery. Cost ranges from 25 to 35 cents 
per square foot, depending largely upon the distance the material 
has to be transported, and the amount of work that has to be done 
preliminary to laying the pavement. 

797. Tar Concrete for Footway Pavements is made in many 
and various ways. Pavements made according to the following 
specifications have proved satisfactory: 

Proportions of materials: 

Steam aslies. 3 parts 

Portlaud cement. 1 part 

Sharp sand. ..... ., 1 “ 

Gas-tar. 9 parts 

Water... 70 to 80 “ 

Method of Mixing. —The ashes, sand, and cement are thoroughly 
mixed dry, then the water and tar added and mixed in the same 
manner as mortar. The plastic mass thus produced is passed several 
times through a pug mill: if this is not done, the concrete will be a 
failure. As the mass emerges from the mill a large proportion of 
the water will run from it, and means must be provided to allow it 
to escape freely. 

The foundation is prepared in the usual manner and the concrete 
laid 3 to 4 inches in thickness, well rammed with hand rammers* 
then rolled with an iron roller weighing not less than 600 pounds— 
the amount of rolling to be not less than two hours for each 100 
square feet. Hollows that appear during the rolling to be trimmed 
and filled up. After the concrete is set sprinkle a small quantity 
of clean, sharp sand over the surface and allow it to remain for three 
or four days after the path has been in use, then remove it. 

The concrete should not be laid in wet or freezing weather. 

798. Another method of forming tar-concrete pavements is as 
follows: On a dry foundation is placed a coat of rough clinkers 
from anthracite coal, or iron clinkers from a foundry, mixed with 
sand and tar in the proportions of 15 cubic feet of fine sifted ashes. 








463 


FOOTPATHS, CURBS, GUTTERS. 

14| cubic feet of pit sand, and H cubic feet or 9 gallons of tar. This 
is laid about 3 or 4 inches thick and well rolled. Over this is placed 
a coating from 1 inch to 1£ inches thick, composed of 15 cubic feet 
of coarse sifted ashes, 15 cubic feet of clinkers, and 1^ cubic feet or 
S gallons of tar. It must then be well rolled and sanded, care hav¬ 
ing been taken that the materials are thoroughly mixed. 

799. Footway pavements of which the binding material is coal- 
tar must only be reckoned as temporary. They have been extensively 
used in several cities, but as a rule they soon wear out and become 
very disagreeable. Under a hot summer sun the pavement becomes 
soft and sticky, the volatile oils are evaporated, and the surface be¬ 
comes covered with ridges; they are difficult to repair and are never 
satisfactory. 

800. Gravel.—For suburban streets, country roads, parks, and 
pleasure-grounds, gravel makes an excellent footway pavement. 

The same rules that apply to the construction of gravel road¬ 
ways apply to gravel footways. They must be well drained and 
well rolled. 

Limestone chippings may with advantage be used with pit 
gravel. For paths formed of gravel a crowning surface looks better 
and is more enduring than a sloping one. (See Fig. 149.) 

801. As examples of excellent rural-walk construction, the walks 
of Central Park, 1ST. Y., may be cited. These walks embrace, in 
treatment and materials, the requirements of the generality of rural 
walks in this country. They are laid on every variety of ground, 
from level and smooth to rocky and precipitous, sometimes clamber¬ 
ing with rustic steps and winding narrowly along rugged hillsides; 
sometimes gently undulating over meadows and lawns, and some¬ 
times expanding into broad and capacious promenades. They are 
carried over and under roads, and over brooks, by archways and 
bridges of various kinds, ornamental and rustic; through gorges 
and ravines, and along the water edge of lakes and ponds. They 
are made of various widths, from 3J to 35 feet, and adapted to 
nearly every circumstance of position, locality, use, and convenience 
that ordinarily occurs in walks for rural or park purposes. 

802. The general method of constructing the walks was as fol¬ 
lows : In the more formal walks—those having the greatest breadth 
and occupying ground that was originally so irregular and uneven 
as to require a considerable amount of excavating and filling—the 





4G4 


HIGHWAY CONSTRUCTION. 


preparation of the "bed of the walk was the same as for the roads. 
Care was taken to compact the earth in the embankments, exclud¬ 
ing all perishable and improper materials. 

The bed of the walk was raised in the centre, with a moderate 
inclination toward the sides, and where not sufficiently firm was 
rolled with a hand- or horse-roller. The sub-drainage was se¬ 
cured by drains formed sometimes of tiles and sometimes of 
rubble-stone, so placed as to intercept and carry off the water from 
rain and springs. “ Mitre drains ” formed of small stones were em¬ 
ployed where necessary. 

803. One of the principal causes of the deterioration of walks,, 
and a prolific source of trouble and expense in repairs, is the wash 
from water brought from the adjoining slopes. If the expense of 
making good the damage done in this way—sometimes by a single 
shower—is considered, it will be seen that a liberal and ample pro¬ 
vision to guard against it is warranted by sound economy. No 
cheaper or more effective and practical method can be adopted for 
this object than the catch-water drains, or, as they have been termed 
in the Park, “ sod gutters/' 

These are made along the uphill side of the walk, in the form of 
a broad grave, parallel for the most part with the walk and a few 
feet from it, and joined by an easy graduation of surface to tho 
ground on each side, so as to give them as little of an artificial 
appearance as practicable. The bottom is made even and regular, 
with no depressions to lodge silt or mud, or form pools of water. 
When properly shaped the surface is sodded and rammed. 

After the grass has taken root, the gutter will bear the passage 
of a considerable volume of water for as long a time as is ordinarily 
required, without receiving injury. This form of gutter admits of 
the mowing of the grass that grows in it without difficulty, which 
is a great convenience. If the walk passes through a hollow, with 
descending ground from each way, these gutters are made on each 
side of the walk. When it occupies ground that is level transversely, 
it is raised slightly above the surface, to give an outward inclina¬ 
tion to the turf borders and turn the water away from it. 

The gutters are conducted along the walk, parallel with it, or 
deviating occasionally to take advantage of convenient natural 
depressions, until a favorable point is reached for turning off the 
water altogether, and disposing of it in a secure manner. Where it 
is practicable, the water is allowed to spread out from the termina- 



FOOTPATHS, CURBS, GUTTERS. 


465 


tion of a gutter upon a broad surface of descending ground,.and 
seek the general drainage courses of the district in which it is situ¬ 
ated, that lead to a sewer inlet, a brook, or a pond. Sometimes the 
gutter is conducted to a sewer or road drain in the vicinity; but 
when facilities of this kind are not available, and it is objectionable 
or unsafe to discharge an accumulation of water upon a lawn or 
through shrubbery, special under-drains have had to be constructed. 
Such under-drains have been necessary, to a considerable extent, in 
connection with most of the main walks of the Park. They receive 
through grated inlets, inserted in the gutters (with accompanying 
silt-basins), the immediate drainage of the walks, and, through 
similar inlets placed in the adjoining sod gutters, the exterior 
drainage. Fig. 161 shows the arrangement of these drains, inlets, 
and silt-basins. The depression on the right of the figure shows in 
section a sod gutter (or a natural surface channel), having an inlet 
to the main and under drain through a silt-basin, which is repre¬ 
sented under the right walk gutter. The inlets and silt-basins 
occur in this manner at intervals of one hundred to three hundred 
feet, according to circumstances, the amount of drainage, the de¬ 
clivity of the walks, etc. The under-drain is carried various dis¬ 
tances along the walk, until it becomes convenient to turn it into a 
larger road-drain or a sewer. 



FIG. 161. SECTION OF PARK WALK, SHOWING THE 
MANNER OF REMOVING THE SURFACE WATER. 


Where the under-drains and silt-basins are omitted, which is the.- 
case with the narrower and more irregular walks, the drainage of 
the surface of the walk is conducted off to the ground beyond, or 
to a sod gutter, through openings in the border of the walk that 
are made at suitable points. 

804. The footway is formed of rubble and small or roughly 











































466 


HIGHWAY CONSTRUCTION. 


broken stones, deposited generally eight inches deep for a founda¬ 
tion, with about two inches of gravel spread over the top to receive 
the wear. The stones are such as are obtained from the earth 
excavations in grading the walk and adjoining grounds, or from 
blasted rock and bowlders, or field stones picked off the surface of 
the ground, or cobble-stones thrown out from gravel excavations, 
etc., as may be found convenient in any case. Blasted or quarry 
stones are preferable when they can be had in sufficiently small 
sizes, and without incurring the expense of quarrying them specially 
for the purpose. The sizes should be such as to admit of making 
up the layer of eight or ten inches deep, in two courses, or so that 
no single stones shall reach through the whole layer, and prevent 
the effectual closing of interstices. Quarry stones are better than 
field stones, for the reason that they are more angular and irregular 
in shape, and make a more open or cellular foundation to facilitate 
the drainage and prevent the action of frost. 

805. A bed of stones laid in such a way as to permit the sur¬ 
rounding spaces to be filled up, either by the wash of mud along 
the bottom, or by the sinking of the stones in the bottom (in con¬ 
sequence, frequently, of defective drainage), or by the gravel or sur¬ 
face material working down from above, is but little better than a 
bed of natural stony ground, for it absorbs and retains all the water 
that reaches it, until it fills up and overflows at the surface, making 
the walk wet and spongy, and inviting all the difficulties and de¬ 
teriorating results that it is a principal object in constructing 
walks to guard against. Walks are frequently observed that have 
been made in this way—a mass of stones having been thrown to¬ 
gether in a trench on wet ground, with considerable trouble and 
expense, and the unprotected interstice^ filled solidly with mud that 
has been washed in from time to time (perhaps mostly during the 
process of construction), until no room is left for the percolation 
of water from the surface, and the saturated bed is in a condition 
to be operated upon to the fullest extent by frost. It ought not 
to be a matter of surprise, although it sometimes is, with those who 
make such walks, that they do not give satisfaction at all commen¬ 
surate with the expense and labor bestowed upon them. 

806. When the layer of stones is formed of requisite depth, and 
some pains taken to regulate and adjust the surface by settling, 
breaking, or replacing stones that are too large or that project 




FOOTPATHS, CURBS, GUTTERS. 


467 


too high, and filling with smaller stones or covering the larger 
apertures, a coating is then spread over of quarry chips or such 
finer rubble or coarse gravel as may be available. In case such ma¬ 
terials cannot be had, soft, shelly, or partially decomposed stones 
are selected and broken up on top of the layer, until the interstices 
are sufficiently closed to admit of following the process with a light 
film of gravelly loam or other coarse earth, which latter material, 
after being evenly distribu ted a7id moistened is well rolled by hand- 
rollers. This prepares the surface of the bed—when the work is 
carefully and thoroughly performed—for the reception of the final 
covering of gravel. 

807. The perfection of the work consists, up to this point, in 
forming a stable and unyielding foundation, with the interstices of 
the main body of stones kept free and unobstructed, and a covering, 
to support and retain the superincumbent gravel, of the least thick¬ 
ness and density that will enable it to serve its purpose. A fair test 
is afforded of the sufficiency of the surfacing material by letting the 
work stand, after the rolling is done, until it has been exposed a 
few days to the weather: if it sinks away into the stones below, 
forming holes and leaving the stones naked and roughly project¬ 
ing, it shows that enough material has not been added, and such 
spots should be well repaired; if it retains water (from rain), form¬ 
ing a muddy surface that does not filter away and dry out readily, 
it shows that more earthy material has been used than is beneficial. 
The proper surfacing of the bed of stones will not ordinarily add 
much to the average depth of the layer, just covering the highest 
points of the stones, and filling over smoothly the intervening in¬ 
equalities, so that the gravel, when it is applied above, will have a 
uniform depth and conform to the desired crowning shape of the 
walk. 

808. If gutters are required for the walk, the foundations for 
them are prepared by using, in the outer edges of the stone filling, 
smaller stones and gravel for the better support, and to facilitate 
the setting of the gutter stones. 

809. The gravel is deposited on the walk two or three inches 
deep, the coarser part being raked forward into the bottom of the 
layer, and such pebbles as are too large picked off. When evenly 
adjusted, a film of sandy or clayey loam is spread over the surface 
and lightly raked in to aid the binding effect, and after the whole is 




4G8 


HIGHWAY CONSTRUCTION. 


moderately watered or moistened, the completing process of rolling 
and compacting is commenced. This is done, on the principal 
walks, by a roller drawn by a horse; on narrow walks and those 
having greater acclivities, regularities, rustic steps, etc., it is done 
by a roller of less weight, drawn by hand, by two, three, or four 
men, as the case may be. As the rolling proceeds, a man follows 
with a rake, to correct inequalities and keep the binding material 
equally diffused through the gravel, and to add more of such mate¬ 
rial, from time to time, as may prove to be necessary. Judgment 
and expertness are required to manage this business well. Dull or 
unpracticed men will waste their time at it. The quantity of 
binding material that is judicious to use will vary sometimes with 
each load of gravel: if too much is used, or if it is unevenly and 
carelessly spread, it will produce an imperfect surface, and it will 
take considerable time and labor ro correct after the walk is brought 
into use. If the gravel is fine and filled with dirt, or if the grains 
are of a soft, friable quality, it will not need as much foreign mate¬ 
rial added to make it bind as when it is clean and hard: it may 
contain such a quantity of earthy matter, however (as is frequently 
the case), as to make it necessary to free it from a portion of the 
binding substance by screening, rather than to add to it: such 
gravel should not be used if better can be had. All muck, top-soil, 
and vegetable or fertilizing matter should be carefully excluded 
from both the gravel and the binding material, to prevent the 
growth of grass in the walk. The gravel that has been used in the 
Central Park walks has generally been of a sharp, hard quality, and 
more than usually free from dirt, and it has been found that it 
would bear an average intermixture of about one fifth its bulk of 
loamy or sandy earth to give it the requisite binding property. If 
more than this was added, the work of rolling and packing would 
be facilitated, but the surface of the walk would absorb and retain 
water, and become muddy after a rain; if less was added, the roll¬ 
ing, although it might be thoroughly done, would not suffice to 
make a surface that would remain firm in dry weather. 

810 . The effect of the proper adjustment of these points, the 
selection of a good quality of gravel, the judicious use of the bind¬ 
ing material, and the raking, shaping, and rolling, is to produce a 
walk that is agreeable at all times: not muddy or slimy after a rain, 
or loosened so that the foot sinks into it when it becomes very dry, 
or much subject to dust. 






.FOOTPATHS, CURBS, GUTTERS. 


469 


With care and some sleight in the raking, before and after the 
rolling is commenced, the finer gravel and sand will be worked to 
the top and the coarser pebbles buried in the bottom of the layer, 
preventing the disagreeable feeling that is caused by walking over 
a coarse or unequal surface. 

811. In investigating the subject of walk drainage and gutters, 
in the early stage of the Park work, experiments were tried in 
order to ascertain if some better or cheaper or less objectionable 
description of gutter could be devised than those in common use. 
Although the results attained were not such as to warrant the adop¬ 
tion upon the very uneven grounds of the Park of any of the kinds 
of gutter experimented upon, yet they may afford some hints and 
possess sufficient interest to he worthy of mention. 

The principal kinds were as follows: 

(1) Cement or concrete gutter. 

(2) Composition gutter. 

(3) Iron gutter. 

(4) Wood gutter. 

Nos. 1 and 2 were open gutters. No. 1 was composed of a con¬ 
crete consisting of two parts of gravel and sand and one part of 
cement laid on a filling (adjoining a walk east of the Mall), of 
broken stone and gravel of about 9 inches in depth. The concrete 
was deposited 2 to 3 inches thick, and moulded by the aid of a 
wooden implement drawn over it into the desired form. The 
gravel of the walk and the side border were closed up to it on 
either side, and completed the process. 

This gutter was comparatively cheap and easy of construction, 
and appeared in all respects, as regards utility, well adapted to the 
purpose. After exposure to the weather for a time, it became 
lighter in color than the gravel of the walk, owing to the cement 
which entered into its composition. The objection to it at the 
time of trial (1859) was the uncertainty of its durability, together 
with the general objection to all open or surface gutters—that it 
gave too marked and formal an outline to the walk. The sample 
is still in its original position. It has improved in respect to color, 
and has been but little affected by the changes of weather or frost 
or by wear. 

No. 2, composition gutter, east side of “the Ramble,” was made 
in a similar manner to No. 1 as to form and dimensions, but the 





470 


HIGHWAY CONSTRUCTION". 


materials used and its manipulation were not disclosed by the gen¬ 
tleman who introduced the sample and supervised its construction 
(Gen. Asboth). The principal defect of this gutter seemed to be 
the contraction of the materials, which separated on exposure into 
broken sections—the action of frost and other causes tending to 
increase it and displace the parts. It was also ojien to the general 
objection mentioned to all formal gutters. 

No. 3, iron gutter, was made of light sheet-iron, in sections of 
U-form, with a perforated movable lid or cover. The design was 
to make it a concealed gutter by sinking it along the edges of the 
walk and covering it over with a light layer of gravel—the surface- 
water to percolate through the gravel and the perforations in the 
lid into the gutter, and thence pass off as through a pipe. This 
sample, as far as tried, indicated that it might be made to operate 
well in ordinary cases of moderate drainage and not too great incli¬ 
nation of the walk, but it was considered to be subject to too many 
contingencies for general use. 

No. 4, wood gutter, was constructed upon the same principle as 
No. 3, with the substitution of wood for iron. It was a mere wooden 
trough with a perforated lid, the wood having been subjected to a 
process to give it greater than ordinary durability. It was apparent 
that it was inferior to the iron gutter (though much cheaper), and 
its general want of adaptability was considered as decisive against 
it. 

A method of macadamizing gutters of the common (open) form 
was tried in order to obtain a gutter that would blend, better than 
ordinary paved cobble-stone gutters, with the gravel of the walk, 
and not present the usual contrasts of color and kind of material, 
but it was found impracticable by ordinary means to give the 
materials sufficient compactness and cohesion to resist long the 
action of a current of water. The same process was tried for the 
surface of a narrow walk, on steep ground, where it was difficult to 
make the gravel remain during rains, and with the same results. 

These experiments (although not wholly failures) serve to show 
that the safest and probably the most practicable means that can be 
adopted for the drainage of walks in general are such as have been 
gradually brought into use in the Park, in the manner that has been 
previously described. 

812. General Directions for the Construction of Gravel Walks. 





FOOTPATHS, CURBS, GUTTERS. 


471 


(1) Excavate a trench the width intended for the walk, ten to 
twelve inches deeji, leaving the bottom even and regular and slightly 
crowning in the centre, unless the walk is to be quite a narrow one. 
If the ground is not hard and firm, pass a garden-roller a few times 
over it. If it is wet and heavy, lay a line of H-inch drain-tile 
(using collars) along the walk as near the centre as practicable, and 
at a sufficient depth to be below the reach of frost. 

(2) Fill the space excavated for the walk six to nine inches deep 
with field or quarry stones, placing the smallest on top. Select the 
softest and easiest stones to break, and hammer them up on top of 
the stone filling until the interstices are sufficiently filled to exclude 
the gravel. Kotten or partially decomposed stones will answer well 
for this purpose, or, if this material is not convenient, use a light 
layer of gravelly loam or hardpan. The surface will be further 
improved, previous to putting on the gravel, by sprinkling it and 
going over it a few times with the roller. The object of the process 
thus far is to secure a firm, well-drained foundation for the walk, 
having the surface interstices of the stone filling sufficiently closed 
to prevent the gravel from running down and filling up the voids 
below, and yet leaving free vent for surface-water to percolate 
through. 

(3) If the stone filling is well prepared in this way, and the sur¬ 
face made even,—no points of large stones projecting, etc.,—two 
inches in depth of hard fine gravel will be sufficient to complete 
the walk. In applying the gravel a light layer shoiald at first be 
put on and raked over evenly, working the coarser gravel forward 
into any interstices or inequalities of the stone filling. Moisten this 
layer and roll it down firmly and evenly. The second and last layer, 
to make the most complete and agreeable surface, should be passed 
through a screen the meshes of which are not more than T J g of an 
inch wide, and care should be taken in applying it not to rake up 
the first layer, and to spread it evenly—holding the handle of the 
rake nearly perpendicular. If it is not screened, more pains must 
be taken (with a fine rake) to exclude from the surface gravel that 
is too coarse and unequal in size to be agreeable to the foot. Next 
and lastly, sprinkle and roll the whole thoroughly. The gravel 
should not be drenched, but only made moist or damp in order to 
pack well under the roller. Until the walk has had some wear, it 
will be necessary, after dry weather, to trim the surface anew with 





HIGHWAY CONSTRUCTION. 


473’ 

the back of the rake, and repeat the rolling occasionally. Roll 
after a light rain, but never when the gravel is dry or when too wet. 

(4) A slight intermixture of clay or loam with the gravel will 
serve to make it pack or “ bind ” more firmly when desirable, and 
with less use of the roller; but this should be done with moderation, 
and no vegetable mould should be introduced to encourage the 
growth of grass or weeds. It is a great advantage to procure pure 
gravel: its freedom from earthy or vegetable matter prevents not 
only vegetation from taking root, but the liability to dust in dry 
weather and a muddy or slippery surface in wet weather. It also 
prevents the action of frost. It is better, therefore, to avoid any 
intermixture of other substances that will defeat these objects. 

(5) The surface of a walk should be a little crowned in the 
centre, and should be provided with outlets through the grass 
borders, at suitable points, to carry off sudden accumulations of 
water. Where the walk has much inclination, and also where the 
outside drainage from adjacent ground is liable to be brought to it, 
more frequent outlets, cross-drains, etc., must be made. 

(6) If, for any considerable distance along the walk, drainage- 
water from sudden rains cannot be conveyed away from it securely 
by these means, gutters must be made. These can be made in a 
variety of ways, but there are no gutters that give more permanent 
satisfaction, at a moderate cost, than those formed neatly with small 
cobble-stones. Suitable stones for the purpose can generally be 
selected from the gravel delivered for the walk, or from the pit 
from which it is obtained. 

(7) A system of walks, extending over a large area of ground 
that is not naturally adapted to easy surface drainage, must have 
one or more main under-drains with subordinate or branch drains 
entering them from various points of the system, and with inlets 
from the gutters of the walks, silt-basins, etc., all of which must 
be adapted to the local circumstances in each case by special study 
or survey, and no general rule can therefore be given for their 
treatment. 

(8) A walk can be cheaply made on light, well-drained soil by 
simply removing the turf to the depth of three or four inches and 
filling the space with gravel, raking the coarse forward into the 
bottom and leaving the fine on top. One half of the gravel, in this 
case (in the bottom), may be of inferior quality. 




FOOTPATHS, CURBS, GUTTERS. 


473 


813. Curbstones.—Curbstones are employed for the outer side 
Df the footways to sustain the coverings and form the gutter. 
Their upper edges are set flush with the foot walk pavement, so 
that the water can flow over them into the gutters. 

The materials employed for curbing are the natural stones, as 
granite, sandstone, etc., artificial stone, fire-clay, and cast-iron. 

The dimensions of curbstones vary considerably in different 
localities, and according to the width of the footpaths the wider 
the path the wider should he the curb. It should, however, never 
be less than 8 inches deep, nor narrower than 4 inches. Depth is 
necessary to prevent the curb turning over towards the gutter. It 
should never be in less lengths than 3 feet. The top surface should 
be bevelled off to conform to the slope of the footpath. The front 
face should be hammer-dressed for a depth of about 6 inches, in 
order that there may be a smooth surface visible against the gutter. 
The back for 3 inches from the top should be also dressed, so that 
the flagging or other paving may butt fair against it. 

814. Setting Curb requires care and an experienced workman, 
for as it is set dry, great care must be exercised to set it true to level 
and line. It must be well rammed and bedded or it will sink, turn 
slightly over or move, even months after it has been set. Curb¬ 
stones carelessly set will never present a pleasing appearance. 

815. In localities where stone is not obtainable, artificial stone, 
fire-clay curb, and cast-iron afford excellent substitutes. Artificial 
stone under the name of Asbestine Building-stone is used in some 
of the Western cities: it is manufactured from German Portland 
cement, sand, and broken stone. 

Fire-clay curbing is extensively used with brick pavements: 
some of the usual forms are shown in Figs. 162 to 166. 

Cast-iron is employed in some cities in France; it is cast in 
L-shaped sections, as shown in Fig. 167. 

816. Specifications for Standard Granite Curb (Washington, 
D. C.).—The curbing must be of good and acceptable texture and 
color, dressed 12 inches on the face, 3 inches on the back, and 
chiselled 6 inches deep on the joints, with no projections beyond the 
chiselled portion of the joint; the joint to be at right angles to the 
face and top surface; the top surface to be bevelled £ inch; the 
face and top to be plane surfaces, without depressions or irregulari¬ 
ties. The length must not be less than 6 feet, depth not less than 




HIGHWAY CONSTRUCTION. 


474 


20 inches nor more than 24 inches in any portion of a piece, and 
thickness G inches. The bed of the curb must average not less 
than 6 inches in width, and no excessive protuberance will be al¬ 
lowed on the sides. 

817. Special 8 by 8 Inches Granite Curb.—The curbing must be 
of suitable and acceptable color and texture, dressed on top and the 
full depth on the face, and 3 inches deep on back. The top sur¬ 
face will be bevelled £ of an inch. The face and top to be plane 
surfaces, without bends, twists, depressions, cujis, or other irregu¬ 
larities. It will be 8 inches thick, not less than 8 inches nor more 
than 12 inches deep, and no piece less than G feet long. The joint 
will be chiselled throughout. The bed will be rough-dressed to 
give secure bearing. 

818. Specifications for Bluestone Curb (Washington, D. C.).— 

The curbing must be best North Eiver bluestone, dressed 12 inches 
on the face and 3 inches on back, and chiselled 6 inches deep on 





Fig. 167.—Iron Curb. 





































FOOTPATHS, CURBS, GUTTERS. 


4 rv 

ro 


the joints, with no projection beyond the chiselled portion of the 
joint; the joints to be at right angles to the face and top surface. 
The top surface will be bevelled £ of an inch; the face and top to 
be plane surfaces, without bends, twists, depressions, cups, or other 
irregularities. The length must not be less than 4 feet, depth not 
loss than 20 inches, and not more than 24 inches in any portion of 
a piece, and thickness 5 inches. Each piece must have a bed not 
less in area than the dressed portion of the curb, and no' 'excessive 
protuberance on the sides. 

819. Circular Curb.—Circular curb will conform in all respects 
to the specifications for straight curb, except that it will be cut to 
the required radius. It must be cut to such lengths that three 
pieces will make a 90-degree curve. 

820. Specifications for Curbstones (New York).—The curbstones 
shall be of the best quality of North River bluestone, 5 inches thick, 
and not less than 4 nor more than 8 feet long, and 20 inches deep, cut 
and smooth dressed on the front to a depth of 14 inches, bevelled 
on top to the slope of the sidewalk. Ends shall be accurately 
squared, so as to make close joints the whole depth. 

821. Specifications for Setting Curb (Washington, D. C.).—The 
trench will be dug 24 inches deep and 18 inches wide, to permit a 
thorough ramming. A bed of gravel 4 inches deep will be laid in 
the bottom of the trench and thoroughly consolidated. On this 
bed the curb will be laid to level and grade with close joints and 
even and continuous surfaces. The ditch will then be filled with 
gravel, the first filling to be not more than 3 inches deep, be well 
rammed by rammers or bars so as to give the curb a solid bearing 
under its entire length. Other layers will then be rammed in the 
ditch to within 10 inches of the top of the curb; the layer for each 
ramming to be not more than 4 inches deep. 

The special granite curb will be laid on a foundation of hydraulic 
concrete, as shown in Fig. 168. 

On the gravel-bed the concrete foundation made as prescribed 
for the concrete base for standard asphalt-pavements will be laid. 
This concrete base will be laid of such depth as to permit the 
granite curb (of which the depth will vary generally from 3 to 12 
inches) to be placed upon it and remain at the proper grade. All 
spaces remaining between the curb and the concrete foundation 
will then be carefully rammed completely full with cement mortar 



476 


HIGHWAY CONSTRUCTION. 


or fine concrete suitable for the purpose. The necessary concrete will 
then be added to bring the foundation to the dimensions shown in 
the cut. The work of setting this curb will be done by competent 
stone-masons. If so desired, the contractor will be authorized to 


SLOPE V4" 


V. - . _ . £ 



•«.W. 1 ' [i f T 

v, mm 

rm7jr 


Fig. 1 68.—Granite Curb (Washington, D. C.), 


pji1 5 - 4 ‘- 7 ■ 



r 6" -> 


Fig. 1 69 —Bluestone Curb. 

finish the foundation in front of the curb with a layer of binder as 
Prescribed for the intermediate course in coal-tar distillate pave¬ 
ments, but no extra allowance will be made for such work 

822. Specifications for Artificial Stone Curb and Gutter (Wash¬ 
ington, D. C.).—A combination curb and gutter of artificial stone 


























FOOTPATHS, CURBS, GUTTERS. 


477 


on concrete foundation will be laid on streets, as maybe ordered by 
the Engineer Commissioner. The curb, gutter, and foundation 
will conform with the dimensions given on drawings on file in 
Engineer Department. The concrete foundation will be composed 
of the same materials and will be laid in the same manner as pre¬ 
scribed for concrete foundations of asphalt pavements. The curb 
and gutter will consist of fine concrete composed of one part Port¬ 
land cement, two parts clean sharp sand, and three parts clean 
broken stone not more than 1 inch in their largest dimensions. 
The exposed surfaces of both gutter and curb will be coated 1^ inch 
thick with a cement composed of three parts granulated granite 
(the fragments being of such size as to pass through a quarter-inch 
screen and free from all dust), and two parts of cement. 

The cement used in the manufacture of the curb and gutter 
must conform to the current District of Columbia specifications for 
slow-setting Portland cement. The work will be carried on uni¬ 
formly, and the whole curb completed while in a soft and plastic 
state, so that it will become a homogeneous solid when set. While 
still plastic the curb and gutter will be saw-cut at intervals of 8 to 
10 feet, as may be ordered, to allow for expansion and contraction, 
and to give the appearance of cut stone. 

Contractors may use such methods of moulding the curb into 
shape as they may deem best fitted to the work. The curb and 
gutter when set must conform with the cross-section shown in 
drawing. 

A conduit for electrical conductors, 4 inches wide and 4 inches 
high, will be left at the base of the curb if so ordered by the 
Engineer Commissioner. Hand-holes, to give access to this conduit, 
will be left at intervals of 50 feet, more or less, as may be ordered, 
all to be as shown on the drawings. Man-holes will be constructed 
near each cross-street in accordance with plans and specifications on 
file in Engineer Department. The exact location of each man-hole 
will be fixed by the Engineer Commissioner. The cost of these 
man- and hand-holes, and their frames and covers, must be included 
in the price per linear foot of the “combination curb and gutter^ 
with electrical conduit. 

The curb and gutter must be properly protected from injury 
while setting, and the material used for such protection must be 
removed within twenty-one days from the completion of work, if so 
ordered. 





478 


HIGHWAY CONSTRUCTION. 


The contractor is required by law to guarantee all work for the 
period of five years from the date of the completion of the contract. 

823. Specifications for Dressing Old Curb.—Old curb will be 
dressed by the contractors for street improvements whenever ordered 
by the engineer. 

Contractors will employ competent stone-cutters to do the work, 
and will be allowed the actual cost of the labor employed plus 15 
per cent, for tools, sharpening same, and supervision. Certified 
pay-rolls of men employed and amount paid will be required for 
each street. 

824. Re-setting Curbstones.—The curbstones along the line of 
the work shall be readjusted and brought to the grade, and lines 
given by the engineer, without extra charge therefor. All curb¬ 
stones on the line of the work that are cracked or broken, or other¬ 
wise damaged, shall be re-dressed so as to conform practically in 
form, size, and quality to the requirements of the specifications for 
new curbstones. New stones shall be furnished when necessary, 
without extra charge therefor. 

825. Hollow sidewalk curbs are shown in Figs. 170, 171; they 
are especially designed as a conduit for electric wires or cables or 
for pipes. They are the invention of Mr. E. Greyson Banner, of 
London, England. 

The principle is shown in Fig. 170 in its simplest form. The 
block, a, may be of concrete, through which the channels cc are 




Fig, 170. 


Fig.171. 

HOLLOW CURB. 


moulded, and which are accessible upon the removal of the flag b. 
This flag may be continuous in the case of pipes, but for wires, etc., 
it may be so arranged with hand-holes at short intervals. 

Fig. 171 is a modified section for use where the wires are to be 
kept at a distance apart, for the sake of greater insulation, each 
wire having a separate channel. 






















FOOTPATHS, CURBS, GUTTERS. 


479 


The curb may bo formed in place or manufactured at a factory, 
in which case the blocks, to secure alignment, are made with projec¬ 
tions on one end which fit into corresponding recesses on the other. 

826. Gutters.—In streets covered with broken stone, a stone 
gutter is necessary. It may be formed of either stone slabs or pav¬ 
ing-blocks, the latter being the better. It should be not less than 
18 inches wide. If formed of paving-blocks, the blocks should be 
laid with their length parallel to the curb, bedded on gravel, and 
well grouted in with bituminous cement. 


fV'|l| * v> ,'il* li !. / 

1,1 « 1 1 .» 1 1 » i ; u , H 

It I i 1 J f' 11 1 1 , 1 • L. !| .\ 





p 







Fig. 172. PLAN SHOWING MANNER OF LAYING 

GUTTER-STONES. 


When stone slabs are used, they should be not less than 3 feet 
long, 6 inches thick, and from 10 to 15 inches in width. They 
should be laid alternately (see Fig. 172); for if of uniform width, 
the continuous longitudinal joint between the gutter and the rest 
of the pavement will quickly wear into long deep ruts or grooves, 
which causes severe strains upon the running-gear of vehicles when 
the wheels, having once entered the rut, attempt to leave it. 

The gutter should have the same slope as the roadway, and the 
curb should show seven inches or more above it. 

In streets paved with asphalt granite blocks or bricks the same 
material is used for the gutters; the blocks being laid with their 
length parallel to the curb, instead of transversely as in the street 
itself. 

827. Specifications for Laying Cobble Gutters and Crossings.— 

The cobblestone and flagging will be furnished by the 
along: the line of the work. 

The materials necessary to be removed shall be excavated to a 
depth of 12 inches below the top line of the proposed gutter or 
crossing when fully packed. Any objectionable or unsuitable 
material found below that depth must be removed, and the space 
filled with clean sand or gravel. 



















480 


HIGHWAY CONSTRUCTION. 


All holes or inequalities shall he filled to a proper level with sand 
or gravel well compacted by ramming or rolling. Upon the 
foundation thus prepared shall he laid a bed of good bank gravel, fi 
inches in thickness, thoroughly compacted by rolling or ramming. 
Upon this shall be spread a layer of clean, sharp sand, to serve as a 
bed for the paving-stones, of such depth as may be required to bring 
the work to grade. 

The cobblestones shall be assorted as they are brought upon the 
ground, and no stones that are less than 4 or more than 6 inches 
long, or less than 2 or more than 4 inches wide, shall be used, and 
the several sizes must be laid so as to make an even surface when 
rammed. AVhen thus laid the stone shall be immediately covered 
with clean, fine sand, in proper quantities, and raked until the 
joints become filled therewith; the stones shall then be thoroughly 
rammed to a firm, unyielding bed with a uniform surface and 
proper grade. 

The foundation for the gutter and crossing-flag shall be pre¬ 
pared in the same manner as described for cobble, upon which the 
flag shall be laid with close joints and settled into place solidity in 
such a manner as not to fracture the flag. When gutters are laid 
without curb, selected stones of large size shall be laid to line in the 
position and at the height that the curb would be if laid. This 
course must be laid true to line and grade and with especial care. 
Gutters will generally be 4 feet wide, with 12-inch flagging in the 
centre. 

828. Specifications for Brick Gutters.—Whenever ordered on 

streets to be paved with asphalt, brick gutters will be laid. The 
materials necessary to be removed shall be excavated to a depth of 8^ 
inches below the top line of the proposed gutter. Any objectionable 
or unsuitable material found below that depth must be removed and 
the space filled with clean sand or gravel. All holes or inequalities 
shall be filled, to a proper level with sand or gravel well compacted 
by rolling or ramming. Upon the foundation thus prepared there 
will be placed a layer of hydraulic-cement concrete 4 inches in 
thickness. This concrete layer shall conform, in all resjiects ex¬ 
cept depth, with the concrete base as specified herein for standard 
asphalt pavements. Upon the concrete base so prepared paving- 
bricks shall be placed on edge with their lengths at right angles to 
the curb and breaking joints in the direction of the curb. The 






FOOTPATHS, CURBS, GUTTERS. 


481 


outer edge of the gutter shall be left with alternately projecting 
bricks to tooth into the asphalt pavement. 

The bricks must be so laid that the upper surface will be smooth 
and at the proper grade. 

Immediately after the completion of the asphalt pavement ad¬ 
jacent to the gutter, hot paving-tar shall be poured into the joints 
of the bricks until it rises to the surface. The gutter shall then be 
covered with a sprinkling of sharp dry sand'. If so ordered, instead 
of the hot paving-tar a grouting of Portland cement and sharp 
sand in equal proportions, mixed with a sufficiency of water to 
make a thin grouting, will be used. The bricks for this gutter¬ 
paving will be furnished by at its property yards, 

and hauled thence to the site of the work by the contractor for 
laying them. 

Bricks for gutters may be furnished by the at the site 

of the work. A separate bid is requested for the work if bricks be 
so furnished. 

829. Specifications for Gutter-stones. —The gutter-stones to be 

of stone, not less than 4 feet long and 10 to 10 inches wide, 

and 4 inches thick throughout; to have a smooth surface free from 
winds, seams, or other imperfections; to be cut and squared so as 
to form close joints with each other and with the curb. 

The stones shall be laid, at the grade furnished, on a bed of sand 
2 inches thick. The joints of the stones shall break joint with the 
joints of the curb. The stones shall be laid narrow and wide alter¬ 
nately. The joints shall be filled with a bituminous-cement or 
Portland-cement mortar. 

830. Crossing or Bridge-stones.— Street-crossings are footways 
provided for pedestrians; they are formed of two or more rows of 
stone slabs, usually with one or more rows of paving-blocks between 
them. 

The stone used for crossings should not be less than 3 feet long, 
10 inches wide, and 6 inches thick, with the top surface hammer- 
dressed, the ends cut to a bevel of about 15°, as shown in Fig. 174, 
and dressed so as to form a close joint for the full depth of the stone. 
The reason for bevelling the joints is to cause the traffic to travel 
across the joint instead of along it, and thus prevent the formation 
of the ruts which happens with right-angled joints. The bevelled 
joints must point towards the centre of the intersection, otherwise 
the desired result will not be obtained, and ruts will be formed. 





482 


HIGHWAY CONSTRUCTION. 



Fid. 173. SECTION AT CROSSING, SHOWING GUTTER 
PAVED WITH STONE BLOCKS. 






4 



m 



-.I 111 


■ "/rf" y 


>1 •! 


.'II 


v 


< ill"- ' 


i Hi' 


i l||||fi> 

ft. "" 


iiiiii ii'i' " inn/* m y LT , jk 


, / 
titif 


i 1 



!| I: 




4 % 


H 1 j/P' 


Fig, 174. PLAN OF CROSSING, SHOWING BEVELLED 

JOINTS. 



FlG. 1 75. SECTION OF CROSSING SHOWING GUTTER 
PAVED WITH A SINGLE STONE. 


f 









































































































FOOTPATHS, CURBS, GUTTERS. 


483 


Sandstone is superior to granite for this purpose. 

At street-crossings the bridge-stones should be kept level with 
the curb so that pedestrians may step off the path onto the 
crossing without any drop (see Figs. 173 to 176). 



831. Specifications for Bridge-stones (New York).—Bridge, 
stones to be of bluestone, equal to the best quality of North River 
bluestone, free from seams and imperfections. Each stone to be 
not less than 4 nor more than 8 feet long, except in cases where 
specially permitted, and 2 feet wide, and of a uniform thickness, 
which may vary from 6 to 8 inches, and dressed to a fall on top 
not varying in evenness by more than a quarter of an inch, and on 
the bottom bedded, with sides square and full, and ends cut to a 
bevel of 6 inches in 2 feet, and in special cases to such other bevel 
as shall be directed by the Commissioner of Public Works. The 
stones to be in quality and workmanship equal to the pattern at the 
office of the Department of Public Works, and to be cut so as to 
lay a joint not exceeding one fourth of one inch from top to bot¬ 
tom on the ends and one half inch on the sides. 

The bridge-stones will be carefully inspected after they are 
brought on the line of the work, and all those which, in quality 
and dimensions, do not conform strictly to these specifications shall 
be rejected and must be immediately removed from the line of the 
work. 

83A Relaying Bridge-stones.—The bridge-stones now on the 
street shall be relaid without extra charge therefor. If any are 
found defective, new stone shall be furnished therefor at the ex¬ 
pense of the contractor. The stones so furnished must correspond 
in quality, dimensions, and workmanship to the pattern at the office 
of the Department of Public Works. 



















484 


HIG H W A Y COX ST R U CTI OX. 


833. Prices.—The prices of the materials employed for footway 
pavements fluctuate widely, not only in different but in the same 
localities; therefore the following prices simply exhibit the extreme 
range: 

Cents. 

Bluestone flagging 3" thick, per square foot. 35 to 95 

Granite stone flagging 6" thick,'per square foot. 40 “ 110 

Cement concrete “ “ 12 “ 20 

Artificial stone “ “ 18£ “ 30 

Brick “ “ 9 “ 22£ 

Granite, straight, per linear foot. 85 “ 125 

“ circular, “ “ . 100 “ 137 

Bluestoue curb, straight, per linear foot. 35 “ 91 

“ “ circular “ “ 45 “ 110 

Sandstone curb, straight, “ e * . 35 “ 75 

“ “ circular, “ “ 60 “ 100 

Brick gutters, per square foot. 20 “ 38 

Granite “ “ “ . 40 “ 50 

Granite bridge-stone per linear foot. 70 “ 234 

Bluestone “ “ “ . 60 “ 115 



















CHAPTER XVIII. 


RECONSTRUCTION AND IMPROVEMENT OF COUNTRY ROADS. 

834. The improvement of existing roads may be divided into 
three branches: 

(1) Rectification of alignment and grades. 

(2) Drainage. 

(3) Improvement of the surface. 

The first of these consists in the application of the princi¬ 
ples which have been laid down for the location, etc., of new roads, 
and will include straightening the course by extinguishing un¬ 
necessary curves and bends; improving the grade by either avoid¬ 
ing or cutting down hills and embanking valleys; increasing the 
width where requisite, and rendering it uniform throughout. 

The second consists in applying the principles laid down for 
the drainage of new roads, and in constructing the works necessary 
to give them effect. 

The third consists in improving the surface in the best possible 
manner, either by the forming of an artificial pavement or, if suffi¬ 
cient funds for this purpose are not available, by adopting such 
local materials as will make a comparatively fair surface. 

835. Improving Clay Roads.—Olay soils can only be made into 
fair wheelways by means of thorough drainage effected by any of 
the methods described in Chapter XIV. 

The narrower the roadway the more effective will be the drain¬ 
age. 

If sand, gravel, ashes, coal-dust, furnace-slag, or shells can be 
obtained, a coating of any one of them, 4 inches thick, well com¬ 
pacted by rolling, will form an improvement; if none of these 
materials can be obtained, the clay itself may be utilized by being 
first burned, then spread and rolled. 


485 


486 


HIGHWAY CONSTRUCTION. 


The manner of preparing and using the clay is as follows: In 
summer weather, or during the hot season, the soil in the proposed 
road should be cut out to a depth of two feet into large spits and 
laid roughly one upon the other, and left in that condition for 
about ten days. By this time the sum's rays will have evaporated 
the moisture held by soils of this nature. So soon as the spits are 
dry they are submitted to the action of fire in the following 
manner: A circle is formed fifteen feet in diameter, surrounded by 
a wall made of the roughest and largest spits, two feet high. In 
the inclosure thus formed straw or other light combustible ma¬ 
terial is laid; fagots or small pieces of wood are placed on these, 
and over them are placed other spits, so as to form a cone or 
pyramid, the whole structure to be about 8 feet high. Fire is then 
applied to several parts at once, due care being taken to see that 
the spits sink evenly until the whole mass is well alight. After 
being well banked the mass is left for a day or two, and as soon as 
it attains a good red appearance is drawn down, the wall broken, 
the spits are thrown on top, and others added as required from 
day to day, until all the earth dug has been submitted to the same 
process. In a length of 100 yards of road 20 feet wide thus served, 
it would take about six fires to burn the 12,000 cubic feet contained 
therein. The cost of labor would probably be twenty or twenty- 
five cents per cubic yard. The burnt earth is then, after cooling, 
relaid upon the road, and now, being of a thoroughly porous 
nature, settles into a good, dry, solid layer. 

Before applying any of the above-mentioned materials to a clay 
surface all mud and perishable material must be removed. In 
fact, all the weather-worn clay should be removed to a depth of 
18 inches or more, and the surface thus exposed thoroughly con¬ 
solidated by rolling. 

836. In the maintenance of clay roads neither sods nor turf 
should be used to fill holes or ruts; for, though at first deceptively 
tough, they soon decay and form the softest mud. Neither should 
the ruts be filled with field-stones: they will not wear uniformly 
with the rest of the road, but will produce hard ridges. 

Trees and close hedges should not be allowed within 200 feet 
of a clay road. It requires all the sun and wind possible to keep 
its surface in a dry and hard condition. 





RECONSTRUCTION' AND IMPROVEMENT OF COUNTRY ROADS. 487 

837. Sand Roads.—The aim in the improvement of sand roads 
is to have the wheelway as narrow and well-defined as possible, so 
as to have all the vehicles run in the same track. An abundant 
growth of vegetation should be encouraged on each side of the 
wheelway, for by this means the shearing of the sand is in a great 
measure avoided. Ditching beyond a slight depth to carry away 
the rain-water is not desirable, for it tends to hasten the drying of 
the sands, which is to be avoided. Where possible the roads should 
be overhung with trees, the leaves and twigs of which catching on 
the wheelway will serve still further to diminish the effect of the 
wheels in moving the sands about. If clay can be obtained, a 
coating 6 inches thick will be found a most effective and economi¬ 
cal improvement. A coating of 4 inches of loose straw will in a 
few days* travel grind into the sand and become as hard and firm 
as a dry clay road. 

838. The maintaining of smooth surfaces on all classes of 
earth roads will be greatly assisted and cheapened by the frequent 
use of a roller (either steam or horse) and any one of the various 
forms of road grading and scraping machines. In repairing an 
earth road the plough should not be used. It breaks up the surface 
which has been compacted by time and travel. 

839. Improper Use of Scraping-machines.—The scraping-ma¬ 
chine should not be employed to drag the soft mud out of the 
ditches and place it in the centre of the road. The use of the 
scraper is to remove from the road-surface the weather and traffic- 
worn material which no longer possesses coherence, and which, no 
matter how well rounded up and rolled, will be converted into- 
mud after the first shower of rain. This material, along with that 
removed from the side ditches, must be deposited in such places 
where it cannot be washed back on the road-surface. As it con¬ 
sists chiefly of alluvial and vegetable matter mixed with animal 
excreta, it is useful for fertilizing purposes and may be disposed of 
to the neighboring farmers; but it must not be left in heaps on the 
roadside, to be removed by them at their leisure. 

840. Cost of Constructing Earth Roads.—The following prices 
are taken from the bids received for the construction of wagon- 
roads through the Yellowstone National Park. The specifications 
were: clearing, 30 feet wide; roadway, 18 feet wide and G inches 
higher at the middle than the edges; on each side a berme of 1 







488 


HIGHWAY CONSTRUCTION - . 


foot, with a ditch on the outer side 5 feet wide at top, 2 feet at 
bottom, and 18 inches deep. The roadway to be covered with 9 
inches of clay or earth. 


PRICE PER MILE. 

Highest, $4382. Lowest, $2529. • 

841. Cost of maintaining earth roads ranges from $50 to $80 
per annum per mile. 

842. Value of Improvements.—The improvement of roads is 
chiefly an economical question relating to the waste of effort and 
the saving of expenditure. Good roads reduce the resistance to 
locomotion, and this means reduction of the effort required to 
move a given load. Any effort costs something, and so the 
smallest effort costs the least, and therefore the smoothest road 
saves the most money to every man who traverses it with a vehicle. 

843. Before undertaking any improvement it is generally re¬ 
quired to know the cost of the proposed improvement and the 
benefits it will produce. In the improvement of roads the amount 
of money that may be profitably expended for any proposed im¬ 
provement may be calculated with sufficient accuracy as f'pllows. 
First obtain the following data: 

(1) The quantity and quality of the traffic using the road. 

(2) The cost of haulage. 

(3) Plan and profile of the road. 

(4) Character and cost of the proposed improvement. 

844. Prom the data so obtained ascertain the total annual 
traffic and the total annual cost of hauling it. Next, calculate the 
annual cost of hauling the given tonnage over the improved road, 
which may be obtained from the data given in Chapter X. Then 
the difference between the two costs will represent the annual 
interest on the sum that may be expended in making the improve¬ 
ment. For example, if the annual cost of haulage over the given 
road is $10,000 and the cost for hauling the same over the im¬ 
proved road will be $7000, the difference, $3000, with money at 
per annum, represents the sum of $50,000 that may be expended in 
carrying out the improvement. 

845. For the purpose of ascertaining the amount of money that 
may be profitably expended in improvements, each part of a 
given road must be separately investigated as above directed, 





RECONSTRUCTION AND IMPROVEMENT OF COUNTRY ROADS. 489 


because the amount that may be expended varies with the amount 
of traffic; and as the quantity of traffic using different portions of 
a road varies, the data obtained close to a town cannot be taken as 
correct for distant portions, nor the data obtained for distant por¬ 
tions as correct for portions close to towns. 

846. The defects of existing roads may be stated as follows: 

(1) Unnecessary ascents and descents. 

(2) Unnecessary length. 

(3) Imperfect surface. 

The money benefit accruing from the elimination of any one 
or all of these defects may be approximately calculated as follows: 

847. Profit of Eliminating Grades.—Take for example the 
elimination of a 5^ grade 1 mile long from an earth-road. The 
observations on this grade show that the daily traffic over it is 224 
teams, each dragging an average load of 800 pounds, equivalent to 
24,000 tons per annum; that the time occupied in traversing it 
is half an hour; that the value of a teanTs labor is 30 cents per 
hour. Therefore the cost of haulage on this grade is 33 t 6 q cents 
per ton-mile, or $8064 per annum for the total tonnage using it. 

From an examination of the ground we find that the grade can 
be reduced to 2% by constructing a new piece of road 2 miles long, 
and that the cost of the change will be $18,000. 

From the resistance to traction opposed by the new road-surface 
plus the effect of gravity we find that a team will haul a load, on 
the reduced grade, of 1200 pounds, and that the time occupied in 
travelling the two miles will be one hour. Therefore the cost per 
ton-mile will be 28 cents, or $6720 per annum for the total tonnage. 
To this add the annual cost of maintaining the extra mile of new 
road, say $200; this gives $6920 as the cost per annum, which 
subtracted from the original cost of $8064 leaves $1144; which sum, 
with money at 6^, represents a capital of $19,066, a sum sufficient 
to make the proposed change. 

848. The money loss caused by grades may be approximately 
ascertained as follows: Ascertain the cost of hauling a ton on level 
portions of the same road and on the grade; take the difference 
and multiply it by the annual tonnage: the product represents the 
annual loss. For example, the cost per ton-mile on a level is 22.50 
cents, on a grade 33.60 cents; difference 11.10 cents — loss per 
ton, or an annual loss on a traffic of 30,000 tons of $3330, which is 


f 




490 


HIGHWAY CONSTRUCTION. 


the interest at 6$ on $55,000; which sum the community could 
borrow for the purpose of reducing the grade to a level, pay the 
interest and be no worse off financially, and have a good road 
besides. 

849. Profit of Decreasing Length.—The Profit arising from 
the elimination of any unnecessary length may be stated as follows: 

(1) Saving in time. 

(2) Reduction in wear and tear of horses and equipment. 

(3) Saving the cost of maintenance of such unnecessary portion. 

(4) Reduction in the cost per ton-mile of haulage. 

(5) Saving by the return of the land previously occupied by 
the road to other and perhaps more remunerative uses. 

(6) The decrease in the working time of the horses will permit 
of a slight increase in the load. 

The saving in the above items will vary directly as the distance 
saved. 

As an example take a level road 5 miles long and, neglecting 
the saving in time and rental value of the land saved, and increase 
of load, what will be the effect of decreasing its length one mile ? 

(1) Saving of the annual maintenance of 1 mile. 

(2) Reduction of the time required in travelling over the road, 
thus permitting persons who make several daily trips to make an 
extra trip per day at the same cost for driver and horse-feed and 
with no extra fatigue to the horses. 

(3) Saving in wear and tear of horses shoes, harness, and 
vehicles. 

(4) Saving in the ton-mile cost for haulage. 

Assuming observation of the traffic to show that 100 teams 
drawing average net loads of 2500 pounds use the road daily, and 
that the cost per ton-mile is 20 cents, therefore the annual tonnage 
= 33,480 tons, and the total annual cost of haulage per ton-mile 
= $6096. 

Summing up the items, we have: 


Saving of maintenance 1 mile. $50.00 

33,480 ton-miles, at 20 cents. $6696.00 


6746.00 

Which is equivalent to the interest at 6$ on $112,433, which sum 
could be borrowed to make the improvement. 







RECONSTRUCTION AND IMPROVEMENT OF COUNTRY ROADS. 491 


850. Profit of Improving the Surface.—The benefits accruing 
from this improvement are a general reduction in the cost of 
haulage and wear and tear. The smooth, hard road-surface 
enables the same power to haul a greater load with the same and 
even less fatigue than it can on a rough surface. 

The less the resistance to traction the greater the load, and the 
greater the load the sooner will the produce be marketed. Besides 
the wear and tear on a smooth surface is not one third that on a 
rough surface. 

Assuming that it is required to know how much may be profit¬ 
ably expended in improving the surface of a level earth road one 
mile long, and that the observations show that it is used by 50 
teams per day, each dragging when the road is in good condition a 
net load of one ton, and when in bad condition a net load of 1200 
pounds, and that the cost per ton-mile when the road is in good 
condition is 18 cents, and when in bad condition 39 cents; that the 
road is in good condition for one half the year, and in bad condition 
for the other half; that the cost of paving and improving the 
road will be $7500 per mile,—then we have: 


150 days, at 50 tons = 7500 tons, at 18 cents.= $1350.00 

150 “ “ 27 “ = 4050 “ “39 “ .= 1579.50 

11,550 “ 

Cost of maintaining the earth road. 50.00 

$2979.50 


$2979.50 -4- 11,550 = 25.81 cents, average cost per ton-mile for 
haulage. 

On a broken-stone road in its average condition and at all 
times throughout the year a team of horses will draw a net load of 
3 tons at a speed of 3 miles per hour. If the cost of horses’ labor, 
drivers’ time, etc., be taken at 30 cents per hour, the cost per ton- 
mile will be 10 cents, or for the 11,550 tons annual traffic $1155; 
to which add for annual maintenance of one mile of road $350. 
The annual cost will therefore be $1005, which deducted from the 
former cost of $2979.50 leaves $1375, which, with money at 6$ 
is equivalent to the annual interest on $22,916, which sum may 
be expended in improving the road-surface one mile long. 

The annual loss occasioned by the waste of motive power on 








492 


HIGHWAY CONSTRUCTION. 


unimproved road-surface is clearly shown by the above calculations. 
In the best condition of the earth road it required 50 teams to move 
50 tons; on the improved surface but 17 teams are required to per¬ 
form a like work, and the labor of the teams formerly required 
may be more profitably employed at other work. On the earth 
road in its worst condition it required two teams to move one 
ton; on the improved surface but one team is required to move 
three tons. 

851. Any calculations made to ascertain the benefits accruing to 
a community from improved roads must necessarily fall far short 
of the truth, since no account can be taken of the saving in wear 
and tear of horses and vehicles, of the saving in time caused 
by the increased size of the loads, which thus decrease the number 
of days on which hauling must be done, thus allowing the time to be 
more profitably employed, or of the enhancement of the value of 
the land in consequence of the improved roads, or of the social 
advantages arising from their improvement. 



CHAPTER XIX. 


MAINTENANCE.—REPAIRING ; CLEANSING : WATERING. 

852. Maintenance.—The maintenance of a roadway is the 
keeping of it, as nearly as practicable, in the same condition as it 
was when originally made: the repair of a roadway is the work 
rendered necessary to bring it up to its original condition after it 
has become deteriorated by neglect to maintain it. Thus there is a 
wide distinction between the two operations, and when the com¬ 
parison of costs is instituted errors are frequently caused by 
setting the repairs of one road against the maintenance of an¬ 
other or vice versa. 

853. Necessity for Maintenance.—No matter how well made a 
structure may be, or how carefully the materials used have been 
inspected, the use of it will exhibit defects which it is almost im¬ 
possible to guard against, such as variableness in the quality of 
the material and slighting on the part of the workmen. Moreover, 
every material, whether natural or artificial, is continually under¬ 
going a process of deterioration by the action of the elements: this 
decav is hastened or retarded in proportion to the means employed 
and care bestowed to arrest it. The materials employed for pave¬ 
ments are not only subjected to the destroying action of the 
elements, but also to abrasion and concussion, which by themselves 
are powerful destroying agents. In view of these facts the con¬ 
tinual presence of workmen engaged in repairing pavements must 
not in all cases be considered as evidence of defective construction or 
improper materials, but as an honest endeavor by those in charge of 
the highways to preserve the surface in good travelling condition. 

854. The essential requisite to the preservation of a good sur¬ 
face is eternal vigilance on the part of the roadway keepers. If a 
depression appears in consequence of settlement, defective material, 

or other causes, it must be at once eliminated; if not, it will be 

493 


494 


HIGHWAY CONSTRUCTION. 


quickly deepened and enlarged by each succeeding vehicle, and 
will thus become an obstacle to safe travelling. 

855. Good Maintenance comprises: 

(1) Constant daily attention to repair the ravages of traffic and 
the elements. The character and quantity of these repairs will vary 
with the character of the pavement and the manner of its construc¬ 
tion. With granite blocks laid on a concrete foundation they will 
be the least, with broken stone they will be the greatest; the other 
materials, as wood, asphalt, and brick, lying between. 

(2) Cleansing, i.e., removing the detritus caused by wear, horse- 
droppings, and other refuse finding its way into the streets. 

(3) Watering to lay the dust. 

856. Systems of Maintenance.—Three systems of maintaining 

pavements are in vogue: 

(1) By contract, at a fixed price per square yard per annum for 
a fixed period. Under this method asphalt pavements are main¬ 
tained in both the United States and Europe. Wood pavements 
are also maintained under this system in Europe, but rarely in 
America. The form of contract under which this system is carried 
out in Europe is given in Articles 214 and 265. The advantage of 
this system is that of having some one admittedly responsible for 
the condition of the pavement. Its defects are (g) the difficulty of 
determining the exact condition the pavement is in at the expira¬ 
tion of the contract, (b) It is an extremely costly system. 

(2) By independent contracts for the labor and materials, the 
tools and supervision being furnished by the city. 

(3) By men in the employment of the city, materials, etc., 
being purchased in the open market. This is the system adopted 
by the city of Liverpool, and the excellence of that city’s pavements 
needs no comment. 

857. Maintenance of Country Roads.—When a country high¬ 
way is finished and thrown open to traffic, it cannot be left to take 
care of itself; if it is, it will soon deteriorate and become bad. It is 
to the thorough appreciation of this fact that the excellence of the 
European roads is due. Upon its completion a system of main¬ 
tenance must be instituted. Three systems are in vogue: (a) By 
contract with private parties, (b) Personal service by the rural 
population. ( c ) By men permanently employed for the purpose 
by the community. 



MAINTENANCE.— REPAIRING; CLEANSING; WATERING. 495 


(a) The contract system is unsatisfactory, from the difficulty 
of getting a proper observance of the terms of the contract from 
the contractor or his employers. 

In Austria during the last century experiments were made with 
the letting of the maintenance of the state roads to private parties, 
which experiments proving unsatisfactory, caused the government 
to take the work in hand, and it has adhered to this practice up to 
the present day, with a short interruption in the years 1858-18G1, 
during which time the keeping of the roads was again let by con¬ 
tract, and again gave unsatisfactory results. 

(b) The personal-service or labor-tax system is not applicable to 
the maintenance of improved roads. In fact, it is not applicable to 
any class of roads; it is unsound in principle, unjust in its opera¬ 
tion, wasteful in its practice, and unsatisfactory in its results. 

(c) By men permanently employed for the purpose by the com¬ 
munity. This system has been adopted by France, Germany, and 
nearly all European countries. Its advantages are many. The 
men so employed become familiar with the peculiarities of their 
sections and ivith the best way to deal with them, and good men 
soon learn to take an interest in the road which it is their business 
to keep in order. "It is in vain to expect the same skill or in¬ 
dustry from men employed by the job, or having no interest in the 
goodness of the road, or in making the most of the means at their 
disposal/’ 

858. The maintenance or keeping of the road in proper order 
consists of: 

(1) The daily removal of the detritus either in the form of dust 
or mud, the horse-droppings and other rubbish. 

(2) The filling of ruts or depressions. 

(3) The cleansing out of the ditches, catch-basins, and water¬ 
courses. 

(4) Watering the surface in dry weather. 

The disintegrating action of the weather and the friction of the 
traffic produces dust; this dust renders the road heavy for traffic 
and annoys passengers and horses. If rain falls, the dust is con¬ 
verted into mud. A well-swept road produces no mud after a rain, 
at least not for several days. However, if the humidity continues, 
the road-surface becomes at first sticky and finally is covered with 
mud. Mud makes the tracks of wheels apparent; other vehicles 






49 G 


HIGHWAY CONSTRUCTION. 


follow in them, and after a while ruts are formed which injure 
the road. Thus it is essential that the dust and mud be removed 
from the road-surface. The dust may be removed by sweeping, 
the mud by scraping. These sweepings and scrapings should not 
be left on the sides of the road to be redistributed by the first 
wind, but should be immediately removed: they might be utilized 
by the farmers as an adjunct to their manure-pile. 

(1) The best time for sweeping is early in the morning before 
the dew has dried; besides, there is less inconvenience to the traffic 
at that time. 

The removal of dust and mud may be effected either by brooms 
and hand-scrapers or by mechanical sweepers and scrapers drawn 
by horses. In the rural districts the former will be most suitable, 
while in the vicinity of towns the latter will be most economical. 

(2) Daily attention must be given to the making of slight 
repairs such as filling ruts and depressions; for, however well the 
materials may be laid and rolled, the traffic will search out the 
places which are weak or have escaped the full pressure of the 
roller. 

(a) All ruts should be at once filled. If there are three parallel, 
the centre rut should be first filled. The traffic is thus slightly 
diverted, as a horse will avoid new metal. 

(b) Depressions or hollows should be filled at once. The sur¬ 
face of the road should never be allowed to lose its regular section. 

(c) If the surface of the road where these patches are to be 
placed is very hard, it must be loosened up with the pick. 

(d) Water lodging in a depression should not be let off by 
digging a trench with the pick-axe to the side of the roadway. The 
depression should be filled up. 

( 0 ) All loose stoues should be picked off at once and stored for 
use in filling hollows. If allowed to remain, they are not only dan¬ 
gerous to horses, but are liable to be crushed or to be forced through 
the skin of the roadway, thus causing damage. 

(3) At all seasons of the year the gutters should be kept free 
from mud and rubbish of all sorts, and anything that impedes the 
free discharge of the rain-water from the road must be removed. 

The ditches and culverts should be well cleaned out in advance 
of the spring and fall rains. In northern localities, where snow 
lies for some time, the outlets of all ditches and culverts should be 




MAINTENANCE.—REPAIRING; CLEANSING; WATERING. 497 


opened and cleaned out before the spring thaw sets in. In the fall 
all weeds and grass in the ditches should be cut, and the culverts 
and water-outlets left in good shape for the winter. 

All bridges should be examined at least twice a year. 

All structures such as bridges, culverts, and drains should be 
numbered, the numbers being legibly painted on some prominent 
part; and a book should be kept in which the dates and condition 
at periodical inspections are entered. 

Retaining-walls should be examined and repaired at least once a 
year. 

Guard-stones should be reset immediately they become displaced. 

Parapets, mile-stones, and guide-posts should be periodically 
examined, repaired, and reset. 

(4) Watering to lay the dust is essential in summer and occa¬ 
sionally in winter. In summer, during the dry hot weather, the 
road-surface becomes extremely brittle and then should be watered, 
the dust and refuse having been first removed. 

Sometimes, in winter especially, after frost the road gets very 
sticky and picks up freely under passing wheels. It should then 
also be watered and all slush and mud removed. When the dust 
is regularly removed from a road it does not require so much 
watering in dry weather as it otherwise would. 

A road should never be watered unless it really needs it, as too- 
much water is injurious and it increases the wear from traffic. 

The most common method of watering a road is that of carrying 
the water in barrels mounted on wheels or vehicles specially con¬ 
structed for the purpose and distributing it therefrom through a 
perforated pipe. 

859. Amount of Water Required.—Mr. E. P. North found the 
amount of water necessary to keep macadam roads in the vicinity 
of New York from becoming dusty to be at the rate of 71.3 cubic 
feet per 1000 square yards applied twice in a day, or say 143 cubic 
feet per day. In very hot or breezy weather this was not quite 
enough. 

On the Telford roads in New York 25 cubic feet applied four- 
times a day are necessary per 100 square yards, or about 100 cubic 
feet per day. 

One water-cart holding 79 cubic feet waters 35,000 square- 




498 


HIGHWAY CONSTRUCTION. 


yards four times a day, keeping it free from dust except during 
windy weather. 

860. Cost of Maintenance.—The cost of maintenance is very 
variable, being principally dependent upon the degree of perfection 
with which the road has been constructed, but largely influenced 
by the employment of a sufficient number of skilled laborers to 
maintain the surface in proper condition under skilled supervision. 

The cost of maintaining the roads of France varies from $60 to 
$500 per mile, with an average of $150, of which about half is for 
labor and half for materials. 

The following table gives the cost per annum per square yard 
for the maintenance of macadamized streets in different localities: 


Bristol, Eng. 8 to 24 cents 

Charing Cross, London*. . 100 “ 

Glasgow, Scotland... 17 “ 

Leeds, Eng. 20 to 26 “ 

Liverpool, Eng. 24 “ 36 “ 

Manchester, Eng .. 12 “ 40 “ 

Paris, Frauce. 19 “ 258 “ 

Toronto, Can.„. 24 * “ 

Belgium. 4 “ 10 “ 

Germany. 20 “ 80 “ 

* Now paved. 


861. Repair.—When the thickness of the covering is so reduced 
that it is necessary to re-cover it with stone, let it be done in sec¬ 
tions as large as convenient. The stone should be spread and rolled 
in the same manner as directed for building. As a rule, in re-coat¬ 
ing, the thickness need not be more than two or three stones. The 
periods at which re-coating will be required depend upon the 
quantity of the traffic, and will vary from three to five years. 

862. Organization of Road Force.—For the proper care of a 
roadway an adequate amount of skilled laborers permanently 
employed is necessary. This labor should be employed by the 
community, and be under the direct orders and supervision of the 
county engineer. The force should be arranged as follows: county 
engineer, inspectors (assistant engineers), chief foreman, foremen, 
laborers. 

The number of men required will depend upon the amount of 
the traffic. With light traffic one laborer will be required to every 















MAINTENANCE.—REPAIRING; CLEANSING; WATERING. 499 


4 miles; with heavy traffic and a wide road one man will be required 
to every mile. In the spring and fall extra help will be required; 
the extra men should be directed by the permanent roadman on 
each section, whose knowledge of his section will enable him to 
employ them to the best advantage. 

Chief Foreman .—There will be required one chief foreman for 
every 100 miles of road. His duties shall be to superintend the 
entire road management under direct orders from the County 
Engineer, received either from himself or his assistants. He 
shall have no power to engage or discharge any foreman without 
first reporting to the engineer, but shall have full authority over 
the laborers. He shall set out and direct all work for the fore¬ 
men, shall OK the foremen’s requisitions for tools, supplies, 
horse-labor, etc. He shall under no circumstances purchase tools, 
materials, or employ special labor unless the requisition there¬ 
for is signed by the engineer, in cases to avert an accident or to 
save expense alone excepted. He shall walk the district in his 
charge as far as practicable, and carefully take and keep notes of 
work required to be done, inspect all bridges and structures. He 
shall examine the foremen’s book and see that all accounts are 
properly entered. 

He shall keep an order and tool account, a material, team, 
and general expenditure book, also a careful diary of his day’s do¬ 
ings. He shall work the same hours as the workmen, and do his 
utmost to skilfully manage and check all extravagance, filling up any 
spare time in doing necessary work. In the absence of any fore¬ 
man he shall take his place and direct the work until new arrange¬ 
ments can be made. He will have charge of the steam road-roller 
and be responsible for the economical working of the same. 

Foreman .—The best men obtainable should be employed for 
this work. They should have about ten miles of ordinary country 
road to superintend, varying, of course, very much with the traffic; 
they should live as near as is practicable to the centre of their 
sections. They should not be changed from one section to another, 
but be retained permanently in the same section. 

Each foreman should be supplied with a blank diary, in which 
he should write up every day the work he is engaged upon; each 
page so written to be initialed by the chief foreman. This diary 
should always be in his possession while on the road, and should 




500 


HIGHWAY CONSTRUCTION. 


always be ready for examination by the inspector or engineer, who* 
will note in it the date of examination. The foreman will also bo 
supplied with a time-book in which to keep his own and his men’s 
time; also with an account-book in which he will note the recep¬ 
tion and weight of all material, keep an account of all tools, 
extra labor, team-hire, blacksmith and all other accounts of his 
section. 

The foreman shall take all necessary instructions from the chief 
foreman, and in his absence all orders from the inspector or 
engineer must be promptly carried out. They shall work them¬ 
selves and see that the work is properly carried out on their section. 
They shall have no power to discharge or engage any workman 
without first reporting the matter to the chief foreman. 

Tools .—Every foreman should be supplied with the following 
tools for the use of the men under him and himself: shovels, pick- 
axes, spades, hoes, rakes, rammers, wheelbarrows, brush-hooks,, 
axes, scrapers, brooms, stone-sledges, stone-hammers, straight-edge, 
level, line. 

The tools should be repaired by the nearest blacksmith, under 
contract for a year or more at schedule rates, and before any tools 
are repaired the foreman shall give a written order to the smith 
and preserve a duplicate himself. 

Whether the county shall purchase a stone-crusher or not will 
depend upon circumstances, whether stone is to be had in the 
county or not, or whether it can be purchased cheaper. 

Roller .—The proper maintenance of a road cannot be carried 
out without the employment of a roller. If the extent of the road 
will not warrant the purchase of a steam-roller, a horse-roller should 
be secured. Whichever kind of roller is used, its weight should 
not be less than 4 tons and need not exceed 10 tons; the weight 
per inch of width is more important than the gross weight of the 
machine. 

Team-labor and Materials .—All team-labor and materials should 
be supplied under contract. The chief foreman of the section 
will keep the time of all horse-labor and give time-checks for the 
same. If stone is purchased, it should be bought by weight, and 
each load delivered should be weighed on a public weighing 
machine, and the weight-check delivered to the foreman receiving 



MAINTENANCE.—REPAIRING ; CLEANSING ; WATERING. 501 


the material, who in turn will deliver to the carter a receipt in the 
form furnished for the purpose. 

Accounts .—Accounts of all kinds should be sent to the County 
Engineer direct as soon as the work or contract is complete, and 
no account should under any circumstances be passed unless 
accompanied by the necessary order for the work being carried 
out. 

Requisitions for tools, etc., should be sent in by the foreman at 
a fixed date in each month, and a date be fixed for their issuance. 

Snow .—When snow has fallen heavily or is drifting, the road- 
guard must shovel it off the road so as to keep a track open. If he 
is unable to do this with the assistance of hired laborers, he must 
make requisition for extra help. If, on account of continued drift¬ 
ing, the road cannot be kept oii>en,the travel may be temporarily led 
over the adjoining fields, care being taken to mark the location of 
the temporary road by poles and wisps of straw or tree-branches. 
When the weather permits sleighing for some time, loose stones 
and gravel liable to cause accidents are to be removed, and bare 
spots are to be covered with snow. 

When thaw sets in, all snow and ice on the roads must be 
speedily removed. 

County Engineer .—The County Engineer with the aid of his 
assistants will take direct management of all the roads, set out all 
work and give directions to the chief foreman, and, in general, 
superintend the carrying out of all work, make plans and prepare 
estimates for all materials, keep all accounts and perform all in¬ 
cidental duties. 

Storage and Delivery of Broken Stone .—Depots or spaces for 
the storage of the broken stone should be provided along the sides 
of the road; these depots should be close enough together for the 
roadmen to wheel out the stone to the intervening portions of the 
road. 

The contractor should be required to deliver the broken stone 
at each of these depots at such times and in such quantities as the 
engineer may direct. The stone heaped up at the depots should 
not be allowed to encroach upon the road or interfere with the 
gutters; one or two cubic yards will be a sufficient quantity to have 
at each depot. A convenient size for the stone-heaps will be 6 feet 
long, 3 feet wide, and 1| feet high. Such a heap will contain 1 cubic 



502 


HIGHWAY CONSTRUCTION-. 


yard, and the quantity so stored can be ascertained by measurement 
at any time. 

863. Records.—It is very desirable that those in charge of roads 
should adopt some form of record, showing plainly the cost of 
materials, of labor, and of any miscellaneous expenditures connected 
with the maintenance of roads. Comparisons of the total cost of 
different roads, and of the proportion of expenditure for materials, 
and labor, and for other things, would be facilitated, and a step 
would be taken towards gathering statistics relating to road-main¬ 
tenance which are at present wanting in both America and Eng¬ 
land. 

864. Instructions to Roadmen (published by the Road Improve¬ 
ment Association of No. 57 Basinghall Street, London, E. C.) will 
be found useful to roadmen, and are therefore submitted in ex - 
tenso: 

(1) Never allow a hollow, a rut, or a puddle to remain on a road, 
but fill it up at once with chips from the stone-heap. 

(2) Always use chips for patching, and for all repairs during 
the summer months. 

(3) Never put fresh stones on the road if by cross-picking and 
a thorough use of the rake the surface can be made smooth and 
kept at the proper strength and section. 

(4) Remember that the rake is the most useful tool in your 
collection, and that it should be kept close at hand the whole year 
round. 

(5) Do not spread large patches of stone over the whole width 
of the road, but coat the middle or horse track first, and when this 
has worn in, coat each of the sides in turn. 

(G) Always arrange that the bulk of the stones may be laid 
down before Christmas. 

(7) In moderately dry weather and on hard roads, always pick 
up the old surface into ridges six inches apart, and remove all large 
and projecting stones before applying a new coating. 

(8) Never spread stones more than one stone deep, but add a 
second layer when the first has worn in, if one coat be not enough. 

(9) Use a steel-pronged fork to load the barrels at the stone- 
lieap, so that the siftings may be available for “ binding ” and for 
summer repairs. 



MAINTENANCE.—REPAIRING ; CLEANSING ; WATERING. 503 


(10) Never shoot stones on the road, and crack them where 
they lie, or a smooth surface will be out of question. 

(11) Go over the whole of the new coating every day or two 
with the rake, and never leave the stones in ridges. 

(12) Remove all large stones, blocks of wood, and other obstruc¬ 
tions (used for diverting the traffic) at nightfall, or the conse¬ 
quences may be serious. 

(13) Never put a stone upon a road for repairing purposes that 
will not pass freely in every direction through a 2-inch ring, and 
remember that still smaller stones should be used for patching and 
for all slight repairs. 

(14) Recollect that hard stone should he broken to a finer gauge 
than soft, but that the 2-inch gauge is the largest that should be 
employed under any circumstances where no steam roller is em¬ 
ployed. 

(15) Never be without your ring-guage. It should be to the 
roadman what the compass is to the mariner. 

(16) If you have no ring-gauge, remember Mac Adam’s advice 
that any stone you cannot put easily into your mouth should be 
broken smaller. 

(17) Use chips, if possible, for binding newly-laid stones to¬ 
gether, and remember that road-sweepings, horse-droppings, sods 
of grass, and other rubbish, when used for this purpose, will ruin 
the best road ever constructed. 

(18) Remember that water-worn or rounded stones should never 
be used upon steep gradients, or they will fail to bind together. 

(19) Never allow dust or mud to lie on the surface of the road, 
for either of these will double the cost of maintenance. 

- (20) Recollect that dust becomes mud at the first shower, and 
that mud forms a wet blanket which will keep a road in a filthy 
condition for weeks at a time, instead of allowing it to dry in a 
few hours. 

(21) See that all sweepings and scrapings are put into heaps 
and carted away immediately. 

(22) Remember that the middle of the road should always be a 
little higher than the sides, so that the rain may run into the side 
gutters at once. 

(23) Never allow the water-tables, gutters, and ditches to clog 
up, but keep them clear the whole year through. 



504 


HIGHWAY CONSTRUCTION. 


(24) Always be upon your road in wet weather, and at once 
fill up with “chips” any hollows or ruts where the rain may lie. 

(25) When the main coatings of stone have worn in, go over 
the whole road, and, gathering together all the loose stones, return 
them to the stone-heap for use in the winter to follow; for loose 
stones are a source of danger and annoyance and should never be 
allowed to lie on any road. 

865. The French System of Highway Maintenance.—The sys¬ 
tem of highway maintenance adopted by the French, whose roads 
are unexcelled by any is as follows: 

The roads are divided into national, departmental, military, and 
vicinal or country cross-roads. 

The national roads are maintained entirely at the expense of 
the public treasury; the departments provide for the second class 
of roads, and also partly for the military roads; the local cross¬ 
roads are maintained by the communes, or when of higher impor¬ 
tance by the departments. 

The national roads aggregate upwards of 23,180 miles in length, 
of which 1632 miles are paved like a street. These roads average 
in width 16 metres or 52 feet 6 inches, of which 19.68 feet is for 
the wheelway, 19.68 feet for the sidewalks, and 13.12 feet for the 
ditches and embankment slopes. The department roads are not 
quite so wide, their average width being 39 feet. The aggregate 
length of the latter is about 29,167 miles. The military roads 
number 28, and are about 932 miles long in all. They are chiefly 
in the west of France, laid out after the last insurrection of Ven¬ 
dee. The sum of about $6,800,000 is 3 T early expended in making 
new roads or repairing old ones, and $32,000,000 is expended for 
maintenance and inspection. 

The cross-roads are managed by a special branch of the depart¬ 
ment of the Minister of the Interior, a branch which employs 
.about 3000 inspectors and 42,000 workmen, specially charged 
with the duty of keeping these roads in repair. In 1872 these 
cross-roads aggregated 338,273 miles in length and covered a 
surface of about 915,000 acres. To the very considerable sum 
which the communes must apply to the extension and repair of 
these country roads, the government used to add a yearly grant of 
$2,300,000; but since 1873 this sum has been reduced to $1,150,000 
annually. 






MAINTENANCE.—REPAIRING ; CLEANSING ; WATERING. 505 


The care of the national roads is a large part of the duties of 
the “ Engineers of Bridges and Koads ” (Ingenieurs des Ponts et 
Chaussees) and belongs to the portfolio of the Minister of Public 
Works. 

In each department there is appointed by the Minister of 
Public M orks an engineer-in-chief, who has the direction and 
responsibility of the work of maintenance of such portion of the 
national roads as lie within that department. He is also placed in 
charge of some other work in that department; either of rail¬ 
roads, canal or river improvements, or the care of the seaports, 
if such lie in that department. 

Sometimes he is also in charge of the departmental roads, and 
in a few cases of the county roads as well. Under him are several 
Engineers-in-ordinary (Ingenieurs ordinaires ), who are employed 
only in a certain section of the department ; each one having 
charge of the work in an arrondissement. 

There they direct the repairs according to the general plans 
of their chief, but at the same time they are allowed consider¬ 
able latitude to display their ability or originality and follow out 
their own ideas in the details of the work. Their duties require 
them to visit carefully at least four times a year, oftener if 
necessary, every road confided to their care. 

The next grade below the engineers-in-ordinary is that of 
Conductor or Assistant Engineer. 

The conductor has a subdivision comprising a length such 
that he may be able to inspect it in detail at least twice each 
month and still have sufficient time to attend to the other require¬ 
ments of the service with which the chief is charged, i.e., of 
bridges, railroads, canals, seaports, etc. 

The supervision comprises usually from 25 to 50 miles of road, 
according to the distribution and the complexity of their main¬ 
tenance, and of other details connected with them. The con¬ 
ductor makes semi-monthly inspections of the roads under his 
charge, and, further, he makes his tour of inspection on foot. 

He gives orders to the foremen of the different gangs at work 
along the roads. He keeps a record of their work, to see that they 
do a proper amount. If any have been guilty of neglect, he may 
recommend to his chief that they be punished. 

Following each regular inspection he forwards a written report 






506 


HIGHWAY COHSTRUCTIOH. 


to the engineer in charge of that division. He keeps the accounts 
for his division. He is consulted by the engineer in case of the 
receipt of any petition or other affairs upon which his accurate 
knowledge of the division would make him capable of giving 
information or advice. 

If any surveys are to be made, he makes them. He also 
inspects all road material, all of which is furnished by contract, 
and has immediate charge of the construction of all new work. 

The engineer can give no order to the laborers without giving 
it through the conductor. 

In districts where there is much to do he is aided by a second 
assistant engineer. 

This is the grade held by the younger engineers, who have charge 
of the drafting and clerical work in the chief-engineer’s office, and 
also assist in the outdoor work when there is a press of it. 

It is from the ranks of these latter that by promotion the corps 
of assistant engineers or conductors is kept up to the required 
number. Their promotion is made on their successfully passing 
examinations for that purpose. 

Under the conductor comes the road laborer or cantonnier. 
The road laborers are divided into squads of five or six. Each one 
is in charge of an overseer, chosen from one of their number. 

Each of the road laborers has charge of a length of road varying 
from 1% to 24- miles, depending upon the condition of the road, the 
amount of circulation, and the method of maintenance, which 
would depend upon the nature of its construction. 

When there happens to be much work to be done at once, a 
few laborers by the day are hired to assist, but they are reduced to 
the least possible number. 

If there is to be work that will require extra laborers for a 
considerable length of time, they organize another road gang, so 
that the work will be done by regular hands. 

866. Regulations for Cantonniers (Road Laborers). 

Definition of the Work of Cantonniers .—The cantonniers are 
charged with the manual labor connected with the daily main¬ 
tenance of the roads, over a definite length of road, called a canton. 

They must obey, in everything relating to their work, the 
engineers, foremen, and other agents of the administration of 
roads and bridges. 




MAINTENANCE.—REPAIRING ; CLEANSING ; WATERING. 507 


Nomination of Cantonniers. —The cantonniers are nominated 
by the prefect, from a list submitted to the chief engineer, con¬ 
taining three times, or at least twice, the number of candidates 
required to fill the vacancies. They are dismissed by the prefect 
on the advice of the chief engineer. 

Conditions of Admission. —To be nominated a cantonnier it is 
necessary (1) to have fulfilled the laws relating to service in the 
army, and to be not more than 45 years old; (2) not to be subject 
to any infirmity which may hinder daily and diligent labor; (3) to 
have worked on the construction or repair of roads; (4) to have a 
certificate of good conduct from the mayor of the commune or the 
subprefect of the arrondissement. 

Candidates who can read and write will be preferred. 

Chief Cantonnier. —The cantons of the roads in a department 
shall be grouped in districts containing at least six cantons. The 
six cantonniers will constitute a brigade; one of them shall be chief 
cantonnier; he must be able to read and write, and shall be chosen 
from the cantonniers distinguished for zeal, good conduct, and in¬ 
telligence. 

The chief cantonniers shall have a shorter length than other can¬ 
tonniers, so that they may be able to attend to special duties 
allotted to them. They shall accompany the foremen in their 
rounds, and note the orders which may be given by the cantonniers 
of their brigade, and see that the orders are carried out. They shall 
accordingly go over the whole extent of their district at least once 
a week, varying the days and hours of their visits, to satisfy them¬ 
selves of the presence of the cantonniers, and to direct them in their 
work; they shall report to those under whose orders they are more 
particularly placed, and shall furnish to the engineers all the infor¬ 
mation that may be required of them. 

They may be temporarily employed in superintending and keep¬ 
ing account of the works of re-dressing the paved causeways, and 
in directing itinerant gangs of workmen. 

Distinctive Marks of Cantonniers.— Cantonniers shall wear a 
blue jacket and a leather hat, round which shall be a band of copper 
0.28 m. long and 0.055 m. broad, with the word “ cantonnier ” cut 
out in it. The chief cantonniers shall wear besides on the left arm 
an armlet of the prescribed pattern. 

There shall be given besides to each man a mark consisting of 



508 


HIGHWAY CONSTRUCTION. 


a staff 2 metres long, divided in decimetres, shod with iron, and 
furnished at the top with a strong iron plate 0.24 m. wide and 
0.16 m. high, on each side of which shall be shown in letters 0.08 m. 
high the number of the canton. This mark must always be 
set up on the road at less than 100 metres from where the cantonnier 
is at work. 

The Work of the Cantonniers .—The work of the cantonniers 
consists in maintaining and repairing the roads daily and constantly, 
so that they may be dry, clean, and smooth, safe in times of hard 
frost, and of a satisfactory appearance at all seasons. 

To effect this, they must, subject to the orders and instructions 
which may be given them in case of need: 

(1) Insure the flowing off of water by cleansing the gutters, 
pipes, etc., by making small drains for the purpose wherever they 
may be necessary, taking care that these drains should never be 
made in the body of the road. 

(2) At suitable times oj)en and maintain the ditches, regulate 
the sides, throwing the surplus earth on the neighboring ground, if 
there is no objection, or putting it together to facilitate its measure¬ 
ment or removal. 

(3) Remove as soon as possible with a scraper or shovel all liquid 
or soft mud from the whole breadth of the road, even if there be 
neither hollows nor ruts, and collect the mud in regular heaps on 
the sides to be measured, if there is room for it there. 

(4) Spread the mud, when dry, on the sides which have lost 
their shape or have a slope of more than 1 in 25 from the road, and 
throw the surplus on the neighboring fields, if not objected to. 

(5) At the approach of winter redouble attention to all that is 
prescribed in the two preceding paragraphs, to prevent lumps of 
frozen mud. 

(6) In dry weather remove the dust and deposit it on the sides. 

(7) Clear away the snow from the whole breadth of the road, or 
at least from the middle, particularly at places where it.accumulates 
and obstructs the traffic ; throw it immediately on the neighboring 
fields if possible, or collect it in heaps on the sides, so as to show 
drivers of vehicles where the road is. 

(8) Break and remove ice from the road, and scatter sand and 
rubble, especially at the sides and at sharp turnings. 



MAINTENANCE.—REPAIRING ; CLEANSING ; WATERING. 509 


(9) Also break tlie ice in the ditches and remove it where it 
accumulates, so as to threaten flooding of the road in the thaw. 

(10) In the time of thaw assist the flowing off of the water and 
remove pieces of ice, mud, and dirt, so that the effects of the thaw 
may prejudice the traffic and road as little as possible. 

(11) Collect, break, and stack in separate heaps and in a par¬ 
ticular shape all loose stones, and those projecting or only just 
showing if too large, and those near in the neighboring fields which 
can be used for the purposes of the road. Break the materials 
intended for maintenance, if the breaking is not done by the con¬ 
tractor. 

(12) Cut or dig up thistles or other weeds, especially before 
their flowering season. 

(13) Clear away loose stones for the road and everything which 
may hinder the traffic. 

(14) Clean and clear away earth, plants, and extraneous matters 
from the plinths, string-courses, and parapets of bridges, etc. 

(15) Look after the preservation of mile-stones, sign-posts, and 
bench-marks on the road. 

(1G) Cultivate and look after plantations belonging to the State, 
see to their preservation and to that of plantations of private 
owners, straighten provisionally all young trees bent by the wind, 
and do generally all that the welfare of the road demands, con¬ 
formable to more particular instructions given by the engineers of 
the district for carrying out the above general orders. 

Employment of Materials .—On roads in a state of repair the 
road laborers shall conform to the following rules for employment 
of materials. 

The materials shall be made use of as they are required, always 
choosing damp weather for their employment, avoiding wholesale 
coating and throwing down stones at random. 

To proceed regularly, care should be taken to observe in time of 
rain the hollows and tracks of vehicles, which perceptibly alter the 
shape of the road. 

These worn parts should be cleaned and picked, particularly at 
the edges, but only to the depth necessary to insure the binding of 
the materials. The materials arising from the picking should be 
cleared of earth and broken if necessary before being used. 

The filling up of the hollows or wheel-tracks should be effected 



f 


510 HIGHWAY CONSTRUCTION'. 


with the debris and with the necessary quantity of new material 
received through the engineer. It must be carefully beaten so as 
to incorporate it with the lower layer, and then made to conform to 
the contour of the road. The parts thus restored should be main¬ 
tained with particular care until they are completely consolidated. 

With respect to roads which are not in a good state of repair, 
but which nevertheless are open for traffic, one should endeavor to 
keep them in as good a condition as possible by employing, with 
the care which has just been indicated, the materials available. 

All large or projecting stones should be taken out, as they 
cause damage, and they should be broken to a proper size before 
being used again. 

The coatings more or less extensive to be made on worn roads 
will be prescribed by the engineer, who will also decide on the 
materials to be used. The hollows and ruts to be filled up must 
first be cleared of mud and earth, and their surface then picked to 
a depth of from 4 to 5 centimetres (1^ to 2 inches). The materials 
should not be spread except in layers of from 5 to 6 centimeters (2 
to 2^- inches), which should be carefully beaten and consolidated. 

Task-work to be performed .—To stimulate and maintain the 
activity of the cantonniers, the engineers, inspectors, and foremen 
shall assign them work to be performed in a given time, whenever 
local circumstances permit it. A summary of information on these 
tasks shall be entered in that part of the cantonnier’s book re¬ 
served for the instructions of the service. 

Work thus prescribed shall be one of the principal objects of 
supervision by the immediate head of the cantonniers, as well as by 
the mayors and road commissioners. 

Determination of Working Hours .—From the 1st of May to 
the 1st of September the cantonniers shall be on the roads, with¬ 
out quitting them, from 5 o’clock in the morning to 7 o’clock in 
the evening. The rest of the year they shall be there from sunrise 
to sunset. They shall take their meals on the road at hours fixed 
by the chief engineer. The total duration of meals shall not 
exceed two hours, but during great heat it may be prolonged to 
three hours. 

Removal of Cantonniers .—Cantonniers may be removed either 
singly or in brigades, when the needs of the service imperatively 



MAINTENANCE.—REPAIRING; CLEANSING; WATERING. 511 


.require it, to points indicated to them. These displacements shall 
not take place except under an express order from the engineer. 

Compulsory Attendance of Cantonniers in time of Rain, 
Snow, etc.—Rain, snow, or other inclemency of the weather shall 
not be a pretext for the absence of cantonniers; they must in such 
times redouble their zeal to prevent damage and keep the road in 
good condition for the whole extent of their cantons. They are, 
however, authorized to make themselves fixed or portable shelters 
which shall not interfere with the public way or adjoining prop¬ 
erty, but which must be in sight of the road and less than 10 
metres off, so that the presence of the workmen can always be as¬ 
certained. 

Gratuitous Assistance to Travellers. —Cantonniers must render 
gratuitous aid and assistance to drivers and travellers, but only in 
case of accidents. 

Surveillance over Breaches of Highicay Laic. —To prevent as 
much as possible breaches of highway law, the cantonniers shall 
warn travellers and occupiers of the adjoining lands who may be 
disposed to commit them. They shall consequently keep an eye on 
repairs, building, deposits, encroachments, and planting which may 
take place without leave on the highway. They shall report any 
such breaches to the surveyor, either when he makes his rounds, 
or at once by letter or by message through the chief cantonnier. 

Tools icith which Cantonniers must he provided. —Every can¬ 
tonnier shall be provided, at his own expense, with a wheelbarrow, 
an iron shovel, a wooden shovel, a road-pick, an iron road-scraper, 
a wooden road-scraper, an iron rake, an iron crowbar, an iron 
sledge-hammer, and a line 20 metres long. 

The head cantonniers must besides be provided with three bon¬ 
ing rods (rods in the form of a T much employed in European 
countries to range in grades, etc.), with a level graduated to indi¬ 
cate gradients, and with a double metre measure. 

Tools of a Particular Kind to be furnished by the Administra¬ 
tion. —Each cantonnier shall be entrusted with an iron ring 6 
centimetres (2 } inches) in diameter, so that he may ascertain if the 
stones which he has to spread on the road have been broken ac¬ 
cording to the specifications. 

Providing Tools in advance to Cantonniers. —Cantonniers who 
have no means of procuring them can have any tools they require 



512 


HIGHWAY CONSTRUCTION. 


supplied in advance. The repayment of the cost of these tools 
will be insured by the administration by stoppages, which, except 
in cases of dismissal, shall not exceed one sixth of the monthly 
salary. 

Keeping Tools in Repair .—Cantonniers shall keep their tools 
in a good state of repair. If they become negligent in this respect, 
they will be repaired by the administration, and the expenses will 
be repaid in the same manner as for new tools. 

Tools must not be taken to be repaired during working hours.. 
Excuses for absence based upon the necessity of getting tools 
repaired will never be accepted. 

Cantonniers’ Boohs .—Every cantonnier will be provided with a 
book suitably ruled and headed, in which he will make notes on the 
work and conduct of the laborers, any orders and instructions given 
them, and information of the work which has been assigned to them. 
It must be presented by them to the agents charged with the super¬ 
vision of the road, every time they are required to do so, under 
penalty of the stoppage of a day's pay for every time they neglect 
to produce it, or three days' pay in the case of having lost it. 

Means of Verifying the Absence of Cantonniers .—The absence 
and negligences of cantonniers will be verified by the engineers and 
the agents of the administration employed under their orders, who 
will make a note of them in the books just spoken of. Absence 
can also be verified by gendarmes on their rounds, by mayors of 
the parishes in which the cantons are situated, and by road 
commissioners. 

Leave of Absence at Harvest-time .—At harvest-time, when the 
road is in good condition, cantonniers can obtain leave of absence 
from the engineer-in-ordinary, when authorized by the engineer-in¬ 
chief. They will receive no salary while on leave of absence, at the 
expiration of which they must return punctually to their posts or 
they will be immediately superseded. 

Surrender of Book and of Distinctive Badges on Dismissal of 
a Cantonnier .—When a cantonnier is dismissed, he must surrender 
to the engineer his book, his staff, his ring, and the distinctive 
badges which he wears on his arm and cap. Failing to do this 
double the value of these articles will be retained from that which 
is due to him for salary at the time of his dismissal. 

Classification and Salary of Cantonniers .—Cantonniers of 



MAINTENANCE.—REPAIRING; CLEANSING; WATERING. 515 


each department will be divided into three classes of equal number, 
whose salary, for each class, will be fixed by the prefect, on the; 
proposal of the chief engineer. 

The classification will be made each year by the chief engineer, 
on the report of the engineer-in-ordinary, and according to the 
services of the cantonniers during the preceding year. 

The chief cantonniers will be divided into two classes, likewise 
of equal number. 

Their salaries will be fixed, like those of the ordinary canton¬ 
niers, by the prefect, on the proposal of the chief engineer. 

The cantonniers receive frcm $10 to $20 per month, and the 
chief cantonniers receive 20$ more. 

Indemnity for Removal .—Cantonniers who leave their cantons 
by order of the engineer will receive an indemnity of one fifth more 
than their salary, and three fifths for every day they sleep out. 

No indemnity for removal will be allowed to head cantonniers 
except when they go out of the district of their brigade. In this 
case, the indemnity to which they are entitled will be regulated in 
the same way as those which are paid to ordinary cantonniers. 

Annual Gratuities .— Every year, on the report of the engineer- 
in-chief, the prefect may grant to the most deserving cantonnier in 
each district of the engineer-in-ordinary, a gratuity, which shall 
not exceed a month’s salary. 

A similar gratuity may also be awarded to that one of the 
chief cantonniers of the department who shall have rendered 
the best service. 

Fines on Account of Absence .—Every cantonnier who shall not 
be found at his post by one of the agents having a right of super¬ 
vision on the road, shall be subject to a fine of three days' pay for 
the first time, of six days in case of a second offence, and be dis¬ 
missed the third time. 

Those who, without being absent, shall not have done enough: 
work during the month, or who have neglected the duty entrusted 
to them, will be fined enough to pay for repairing any damage 
resulting from their negligence. 

A part of these fines may be granted by the engineer-in-chief, 
on the report of the engineer in ordinary, for the benefit of those 
cantonniers who by their zeal and work have deserved encourage¬ 
ment. 



514 


HIGHWAY CONSTRUCTION. 


867 . The system described above, while emjfioyed throughout 
France for the maintenance of the national roads, is applied to all 
the other roads in but 27 of the 87 departments. 

In three departments the engineer-in-chief has, it is true, the 
direction of the work, but has under him a different corps of 
engineers or commissioners to superintend the work upon the 
county or vicinal roads. 

In 57 of the departments a commissioner appointed by the 
Minister of the Interior has charge of the county or vicinal roads. 
His corps comprises commissioners or trustees in the arrondissements 
and cantons who are appointed by the prefect of the department. 

The ordinary vicinal roads are in the charge of the mayors of 
the communes. The direct agents are inspectors, who are charged 
with the duty of watching this work, and are responsible for its 
proper execution. 

Inspectors .—The chief inspector is under the direct authority 
of the prefect, and he has charge of all the vicinal roads of the 
department, and all the sub-inspectors are under his orders. He 
executes the laws and regulations prescribed, and the inspectors of 
arrondissements have similar power in their own districts. The 
chief inspector may, when he deems fit, order that certain opera¬ 
tions shall be carried out under agents directly under his control. 

Under the law of 183G, the appointment of inspectors of all 
grades lay with the prefect, who might, if he so chose, transfer the 
control of the roads to the government corps of engineers. This 
right of option was taken from the prefect by the law of 1866, 
which included among the duties and privileges of the Council 
General of the department the right to designate to what parties 
should be confided the execution of work upon vicinal roads. The 
laws of 1871 confirmed this right and extended it to departmental 
roads, so that to-day the nomination, organization, and control of 
the staff in charge of department roads of all classes is the exclusive 
right of the prefectural authority, without restriction. 

The inspectors are divided, ordinarily, into inspector-in-chief, 
inspectors of arrondissements, and inspectors of cantons. They 
shall be French citizens and must be at least 21 years of age. 

The law of 1836 prescribes that in each department there shall 
be a commissioner whose duty it shall be to examine candidates for 
the position; and when a vacancy occurs, it is the duty of the pre- 





MAINTENANCE.—REPAIRING ; CLEANSING ; WATERING. 515 


feet to announce the date of such examinations in his department, 
.and send this notice to the prefects of adjoining departments. The 
Minister of the Interior is also notified of all such vacancies and 
changes. 

The duties of the inspectors employed on the vicinal roads are 
to study the projects, arrange the plans, estimate the cost, and 
watch the execution of all road work, under the authority of the 
prefects and the mayors. Their pay is fixed by the Council Gen¬ 
eral; and they are never to be remunerated by a percentage on 
work performed. 

The Laborers .—The workmen for all main department high¬ 
ways and roads common to several communes are appointed by the 
prefect. The mayors of the communes name those employed on 
the ordinary vicinal roads; but as this appointment implies a fixed 
charge upon the commune, his action must be sanctioned by a vote 
of the municipal council. 

Day’s Work of Proprietors .—France has a system of working 
out road taxes, but it is carried out as follows: For work of this 
nature two periods are generally fixed in each year, ranging from 
one month to six weeks in length, each. The mayors of the com¬ 
munes fix the dates, and so arrange it that any work commenced 
can be finished in the specified time. And in connection with the 
inspector of the canton, the mayor also divides the workmen among 
the several roads and fixes the hours for beginning and ending 
work at each place. Five days before the date fixed the mayor 
sends to each laborer working under this system a notice requiring 
him to report at a certain day and hour, upon a certain road, for 
such work as may be there assigned to him. In case of sickness 
the laborer must make this fact known to the mayor within twenty- 
four hours after receiving his notice; and while the mayor may 
postpone the service required, this cannot be extended beyond the 
current year. As an unnecessary number of workmen at any one 
place leads to confusion and embarrassment, it is the duty of the 
mayor to detail at one time and on any one piece of work only a 
sufficient number of laborers to best accomplish a specified task 
without loss of time. If this labor is to be expended on a vicinal 
road of common interest to several communes, the prefect of the 
department designates the time and location of such work. 

Each workman under this system carries to the place designated 



516 


HIGHWAY CONSTRUCTION. 


such common tools as the mayor’s notice may direct. Tools with, 
which the farmers are not ordinarily supplied are furnished by 
each commune from the fund appropriated to public works. All 
beasts of burden must be harnessed, and all vehicles must have a 
driver, and the time of this driver is received as a full acquittance 
for the time of one man. Farmers may substitute for themselves, 
or members of their family, other men hired and paid for by them¬ 
selves. These substitutes must be able-bodied men not less than 
18 nor more than 60 years of age. 

The length of the day’s work is fixed in each department by a 
general rule issued by the prefect, and it varies according to the 
seasons of the year. This day’s work cannot be divided, but must 
be furnished entirely by the laborer. In case of legitimate inter¬ 
ruption by reason of bad weather, the laborers are bound to com¬ 
plete it at the earliest date possible. If the laborer fails to report 
at the hour indicated, or in any way fails to complete his legal 
day’s work, the lost time must be paid for in money, and this fine 
can be legally recovered by the municipal receiver of taxes. 

Works carried out on vicinal roads under the labor-tax system 
are under the direction and control of the mayor of the commune 
in which such roads lie. This functionary is assisted by the in¬ 
spector in organizing his force and commencing work, and each 
day’s work is preceded by a roll-call, compared with the list fur¬ 
nished by the mayor. If any laborer breaks any of the rules fixed 
for the conduct of the work, comes unprovided with the tools called 
for in his official notice, or in any way does not conscientiously per¬ 
form the duty assigned him, he can be sent from the work, and the 
value of his services, or the proportionate part thereof, collected in 
money. At the end of each day’s work the superintendent of works 
credits each laborer upon his official notice with the number of days 
and class of work done, and at the same time discharges the original 
requisition for labor. After the work is completed this accredited 
notice is signed by the mayor, and sent by him to the municipal 
receiver, and the latter makes the proper entry upon his books or 
register of jorestataires. 

In case a commune neglects or refuses to vote the number of 
days’ work necessary on its roads in the proper time for perform¬ 
ance, and the sub-prefect advises the prefect of this fact, it shall 
be the duty of the latter official to serve a special notice upon the 



MAINTENANCE.—REPAIRING ; CLEANSING ; WATERING. 517 


mayor of the defaulting commune demanding that he execute the 
required work within the specified time. This same notice also 
notifies the farmers that unless the work is well done in the time 
fixed, its value will be required from them, in money. This notice 
must be made public by the mayor; or in case of his refusal by a 
special agent of the prefect. All work of this character is done 
under the supervision of an inspector appointed by the prefect or 
sub-prefect, and the certificate of execution is delivered by the 
mayor on the certificate of this inspector. If the mayor refuses 
to do this, the certificate of the inspector himself is valid. 

Task-work by Proprietors .—Task-work has certain advantages 
over work by the day, for the laborers are free to select their own 
time, and bv more active exertions thev can shorten their hours of 
labor. When the municipal council of a commune has arranged a 
basis upon which it can convert day’s work into task-work, and this 
schedule has received the approval of the prefect, the mayor of the 
commune may decide, so far as the smaller roads are concerned, 
whether work in his commune shall be done by one system or the 
other, as he may deem best. This decision is binding upon all the 
prestataires who have declared their intention of working out their 
taxes. The prefect of the department may in a similar manner 
decide as to the execution of work upon the main highways and 
roads of common interest to several communes. 

When such task-work is to be done, the requisition states the 
class and amount of work and the date by which it must be com¬ 
pleted. The character of work required is further indicted upon 
the ground by the inspector of the canton, and it is carried out 
under his direction. The party assigned to a task is responsible 
for its proper execution; and upon the receipt of the measurement 
and certificate of the inspector that it is properly done and within 
the given time, the mayor accredits the farmer with his task. Work 
improperly done must be done over again, and within a time fixed 
oy the mayor. 

Contract Work .—The mayors, with the authority of the prefect 
for vicinal roads, and the prefect for the main highways and smaller 
roads common to several communes, may let by contract the con¬ 
struction and repair of these roads, But under the law of 183G, 
the proprietors, even when the work is converted into tasks, cannot 
be credited for taxes with work done under the control and for the 



518 


HIGHWAY CONSTRUCTION. 


account of a contractor. Nevertheless, when work on any depart¬ 
ment road is let by contract, the conditions of the contract oblige 
the contractor to receive in return for services the day work or 
tasks of the proprietors according to a conversion tariff approved 
by the Council General of the department in the first case, and by 
the municipal council with the approval of the prefect in the sec¬ 
ond case. 

In cases where the department supjolies this labor in lieu of 
taxes from the laborer and cash paid to the contract or, the de¬ 
partment by its agents makes the requisitions and superintends the 
execution exclusively; the contractors having nothing to do with 
the disposition of the men. But if the prestataires do not carry 
out their obligations, the contractors may call upon the mayor or 
the inspectors to compel the fulfilment of these obligations. 

Cash Work .—In theory all work for which money is paid should 
be executed under a public contract. Nevertheless, with the au¬ 
thority of the prefect certain work may be let by private argree- 
ment under the following conditions: 

(1) For work or supplies when the value does not exceed $600. 

(2) For work when the conditions forbid the delay of a public 
letting. 

(3) That which by its nature requires special skill and experi¬ 
ence on the part of the contractor. 

(4) That which cannot be let by contract after two several 
attempts to do so. Work may also, with the authority of the pre¬ 
fect, be economically carried out either directly under the control 
of the inspectors, or by way of indirect taxes, in cases of urgency 
or when other methods of execution have been recognized as im¬ 
possible or less advantageous. Under these conditions the work 
should, if possible, be accomplished by the task system. 

All projects must be approved by the prefect, and all specifi¬ 
cations for work must contain the clause that the contracts are 
subject to the general conditions imposed upon contractors for 
vicinal roads as annexed to the general instructions issued on 
December 6, 1870. 

The provisional or final acceptance of work performed upon 
main highways or roads common to several communes lies with the 
inspector of the arrondissement, assisted by the inspector of the- 
canton, and made in the presence of the contractor. The accept- 



MAINTENANCE.—REPAIRING ; CLEANSING ; WATERING. 519 

ance of vicinal roads lies with the mayor in the presence of the 
inspector of the canton, two members of the municipal council, 
and the contractor. The contractor is always summoned on these 
occasions, but his absence is no obstacle to the action of the offi¬ 
cials. 

All difficulties arising from disagreement as to work performed 
on vicinal roads, or from damage caused by these works, and not 
arising from a material expropriation of lands, can be adjusted by 
the council of the prefecture, with appeal to the council of state. 

Commissioners of Supervision .—In some departments, the pre¬ 
fects have thought it proper to delegate a portion of the care of 
inspection required by the many details of work on vicinal roads 
to a commission appointed by the prefect and made up from 
members of the General Council, the councils of the arrondisse- 
ments, the mayors, and certain proprietors particularly interested 
in the good condition of the roads. Where a road passes through 
two arrondissements and is too long to be easily watched by one 
commissioner, it may be divided, and its several parts supervised 
by distinct commissioners. Each commission names its own presi¬ 
dent and secretary and fixes the day and place of meeting. When 
the prefect or sub-prefect attends a meeting, he is the president 
for the time being. 

When the prefect thinks best, these commissioners may be con¬ 
sulted upon projects recommended by the inspectors for new 
works, and upon a basis of a division of expenses between the 
communes. They may also designate several of their number to 
take part in the acceptance of work done by contract. Within the 
first three months of the year, these commissioners send to the sub¬ 
prefects their observations upon the state of the roads and point 
out the localities most urgently needing repair. In this report 
they also name the workmen who have most faithfully performed 
their duty, as well as those- who have been careless or slow in the 
performance of their work. 

The Police of the Roads .—No one without previous authority 
can perform any act upon a road that in any way interferes with its 
function as a public way or interrupts travel. And it is specially 
forbidden to make any trenches or openings; to deposit stones, earth, 
or rubbish upon it; to take away any sand, gravel, or other material; 
to spread anything over the road; to divert water channels so as 




520 


HIGHWAY CONSTRUCTION. 


to cause washing of the road; to interrupt in any way the flow of 
water in the ditches, even temporarily; to construct or repair any 
building, wall, etc., bordering upon the road; to open ditches, plant 
trees or hedges along said road, or to dig wells or cisterns nearer 
to the road than provided in the regulations. To perform any of 
these intended acts, authority must first be formally requested. 
Tor all vicinal roads this authority is granted by the mayor with 
the advice of the inspector; and in no case can the mayors give a 
verbal authorization. For main highways and other more impor¬ 
tant roads the authority comes from the prefect, upon the report 
of the inspectors, or from the subprefect under similar advice. 
Every authorization expressly reserves the rights of third parties, 
and stipulates that the roads must be restored to their normal good 
condition. 

Ditches and Slopes .—In giving to the department commis¬ 
sioners or to the Council General the right to give to vicinal roads 
the necessary width, the law of 1871 accorded them the right to 
include all the land required for proper ditches and slopes. These 
ditches must be cleaned as often as necessary, and the expense of 
so doing is charged to the commune; the ditches being a legal 
part of the road, and protected against encroachment in the same 
manner as the road proper. If the authorities have not opened a 
ditch along the whole length of a road, as sometimes happens, the 
bordering proprietors may do so by first having the lines and levels 
given them by the proper parties; without this authority they are 
expressly forbidden to touch the ditches. The care of ditches 
opened for their own protection and convenience lies in the hands 
of the proprietors. 

Rural Roads .—Outside of the vicinal roads properly so called, 
there are in all communes a certain number of minor roads or 
means of communication which, while of little importance, per¬ 
haps, must yet be carefully maintained, as they may lead to a 
public fountain, a watering-place for cattle, or to common pasturage. 
Such roads are termed rural roads in the law of 1839, but they are 
really public roads in the sense that their use is open to all, that 
they cannot be claimed as private property by the owners of 
adjoining soil, and that they are legally under the care of the pub¬ 
lic authorities and are maintained in the same manner as are other 
roads of the commune. 




MAINTENANCE.—REPAIRING ; CLEANSING ; WATERING. 521 


The method adopted is to map every road and every public path 
in the commune, and expose this plan for one month at the office 
of the mayor of the commune. Any objections made to the correct¬ 
ness of the plot or claims of private ownership of roads shown are 
submitted to the municipal council, which is to sift out those having 
a basis of fact. And this same official body renders an opinion upon 
the degree of utility of the roads shown, and the possibility of sup¬ 
pressing certain ones so that the soil may be sold for the benefit of 
the commune. The map with the report of the municipal council 
is then submitted to the prefect of the department, who examines 
it to see that no vicinal roads have been included under the head 
of “rural.” The opposition to the official dedication of a certain 
road may be founded upon a claim of property, or upon the fact 
that it is not public. The property claim is decided in the courts 
of justice; the second case must be decided by the administrative 
power, that is, the prefect. 

When a minor road of this kind is definitely classified as a 
“rural road” it is public property, and the administrative author¬ 
ity itself cannot restrain travel on it except in case of absolute 
necessity. If a commune wishes to enlarge such a road, it can do 
so only by an amicable agreement with the owner of the necessary 
land, unless the prefect officially classes it among the vicinal roads. 
If a rural road is suppressed, the soil can be sold for the benefit of 
the commune; but in such case the proprietors bordering on such 
a road can either demand that the use of it be continued to them, 
or that the commune provide some other passage or pay them an 
indemnity. 

868. Street Cleansing.—Although circumstances legitimately 
determine the intervals at which streets shall be cleaned, neverthe¬ 
less clean, well-swept streets not only add materially to the pros¬ 
perous appearance of a town, but they also have a very marked 
influence upon the health- and morals of its inhabitants; wet and 
muddy, badly-formed, ill-drained streets cause dampness in the 
subsoil of the dwelling-houses in the vicinity and a humidity of 
the atmosphere, both of which tend to produce a low standard of 
health in their neighborhood, irrespective of the wet surface 
through which pedestrians have to wade whenever they are obliged 
to cross such streets. 





HIGHWAY CONSTRUCTION. 


KO< 

O r* / 


Dusty streets, too, are very injurious from the gritty silicate- 
loaded air arising from them. Such an atmosphere when inhaled 
is known to produce disease of the lungs, even when free from the 
dust arising from horse-droppings or other organic impurities. 

869 . The dirt-producing causes common to all roadways are: 

(1) Detritus produced by the attrition of the paving material, 
horseshoes, wheel-tires, and shoe-leather. This cause cannot be 
eliminated. 

(2) The horse-droppings, which add an offensive element to the 
body of street dirt, are, if collected at once, valuable as manure. 
This is done by the street orderly boys in London. If properly 
cared for, it would undoubtedly afford an income greater than the 
cost of collecting it. 

(3) Dirt forced up through the joints of block pavements. 
Under modern specifications the joints of block pavements are 
intended to be closed with a water-proof material. This of course 
would give full protection against this source of dirt, but in the 
majority of block pavements it is doubtful if this requirement is 
ever faithfully performed. A few months generally suffices to dis¬ 
lodge the imperfect filling, and the material of the substratum 
quickly shows itself on the surface of the pavement. 

(4) House and shop refuse carelessly swept into the streets is an 
ever-present source of street dirt. London imposes and enforces a 
fine of not less than $25 and not exceeding $200 upon any person 
sweeping or throwing any refuse, dirt, ashes, dust, deca}^ed fruit, or 
offensive matters of any kind upon the foot or carriage ways. Also 
any person refusing to have the dust or ashes removed by the 
scavengers or obstructing them in the performance of their duties 
is liable to a penalty not exceeding $25. Again, the method of 
removing house-refuse is a prolific source of street dirt. The re¬ 
ceptacles containing it are brought out and are placed on the edge 
of the curb long before the cart makes its appearance or can be rea¬ 
sonably expected to do so. 

870 . The result of these receptacles, filled with heterogeneous 
collections of house-refuse, being left unprotected in the public 
streets is that their contents are quickly strewn about the surface 
of the street, by their being upset accidentally or purposely; and 
the appearance of tire street, which has probably been carefully 



MAINTENANCE.—REPAIRING ; CLEANSING ; WATERING. 523 

swept and garnished during tlie niglit or early in the morning, 
quickly assumes, especially in a high wind, a very offensive char¬ 
acter, and probably has to be re-swept and cleansed before the ordi¬ 
nary traffic of the day commences. 

871. With good pavements the amount of refuse to be removed 
is reduced to a minimum. With pavements the wear of which 
is practically nothing, the dirt consists principally of manure, 
which has a ready sale. The reduction in the amount of unsala¬ 
ble refuse is an object to be sought for; its collection and dis¬ 
posal is an expensive item. This reduction can only be effected by 
the adoption of impermeable pavements. 

In Berlin and Liverpool the average quantity of refuse col¬ 
lected by sweeping has been continuously decreasing in spite of 
increased traffic and area, this reduction being due to good pave¬ 
ments. 

872. Composition of Street Dust.—The following analysis of 
street dust is given by Mr. H. G. Hanks, State Mineralogist of Cali¬ 
fornia. The samples, examined under the microscope, contained 
vegetable fibre, principally horse-manure and the decaying debris 
of Oregon pine and redwood planking, bits of coke and coal, glass, 
horse-hair, quartz sand, some blue particles the nature of which 
could not be determined, and a dark-colored, finely-divided, half- 
dried mud which was pleasant neither to the sense of sight or smell. 
A portion mixed with distilled water and placed in a bottle swarmed 
with life in forty-eight hours. 

Professor Tyndall has also shown that dusty air is alive with 
the germs of the bacteria of putrefaction, whilst the pure fresh air 
which he gathered on a mountain peak in the Alps is devoid of 
such germs, and is absolutely powerless to produce any organisms. 
Persons living in streets that are improperly swept or watered are 
unable to open doors or windows with impunity by reason of the 
dust. 

Dr. Letherby, in 1867, analyzed dry mud from the streets of the 
city of London—dried by exposure for many hours to a tempera¬ 
ture of from 266 to 300 degrees Fahr. At the same time he ana¬ 
lyzed, for comparison, well-dried, fresh horse-dung and common 
farm-yard dung. The results of the analyses of the mud from stone 
pavements are given in Table LXXXV. 




524 


HIGHWAY CONSTRUCTION. 


TABLE LXXXY. 

Composition of Mud from Stone-payed Streets, Horse-dung and 

Farm-yard Dung. 

(Dried at 300 degrees Fahr.) 


Constituents. 

FresluHorse- 

dung. 

Per cent. 

Farm-yard 

Dung. 

Per cent. 

Mud from Stone-paved Streets. 

Maximum 
organic 
(dry weather). 

• Per cent. 

Minimum 
organic 
(wet weather). 
Per cent. 

Average. 
Per cent. 

Organic. 

Mineral. 

82.7 

17.3 

69.9 

30.1 

58.2 

41.8 

20.5 

79.5 

47.2 

52.8 

100.0 

100.0 

100.0 

100.0 

100.0 


The higher proportion of mineral matter in wet weather proves 
that in such weather the abrasion of stone and iron is greatest. 
Dr. Letherby estimated that the average proportions of stone, iron, 
and dung in the muds were: 

Horse-dung. 57 per cent 

Abraded stone. 30 

Abraded iron. 13 

100 per cent 

The mud was so finely comminuted that it floated freely away 
in a stream of water. 

In the mud of wood pavements, the proportion of organic 
matter in the dried mud was larger than in the mud of stone pave¬ 
ments. It amounted to about 60 per cent. 

The amount of moisture in the street mud varied according to 
the state of the weather. 


Stone Pavements. Moisture. 

In the driest weather.rarely less than 35 per cent 

In ordinary weather. “ “ “ 48£ “ 

In wet weather. “ “ “ 70 to 90 “ 

873. The detritus of the material of a granite pavement con¬ 
stitutes but a very small proportion of the total quantity of mud- 































MAINTENANCE.—REPAIRING ; CLEANSING ; WATERING. 525 


forming dust. Colonel Haywood exemplified this proportion in 
an interesting manner, taking the instance of the granite pavement 
of London bridge,—3-inch Aberdeen granite sets,—which was re¬ 
moved in 1851, after having been down nine years. The average 
loss of granite over an area of 3950 square yards, he estimated, was 
equal to 2 inches of vertical wear. The total volume of granite 
worn away was therefore about 219^- cubic yards, assuming that 
the surface was a continuous mass of granite, though there was of 
course a considerable superficial area of joints. Assuming that 
the granite worn off was reduced to the state of fine powder, it 
was increased in bulk probably one hal , and its volume had been 
(219| X 1-J- = )329^ cubic yards. Adding 5$ for the loss upon 
stones removed and replaced from time to time, the total quantity 
worn off and reduced to powder and carried away, mixed with the 
dust of the street and mud, would only have amounted to 345.7 
cubic yards for nine years, equivalent to a wear of .105 cubic yard 
—about a tenth of a cubic yard—per day. Whereas the quantity of 
dust removed daily in dry calm weather was from 3 to 3J cubic 
yards—over thirty times as much as the granite detritus. So much 
for horse-droppings and shoe-leather, which must have constituted 
twenty-nine thirtieths of the total accumulation, independent of 
the contributions of house-refuse, in the inhabited streets. Table 
No. LXXXVI shows the number of cubic yards of street-refuse 
collected in a few cities. 


TABLE LXXXVI. 

Amount of Refuse collected from City Streets. 


City. 

Street Mileage. 

Refuse removed. 
Cubic yards. 

Baltimore. 

. 


780 

180,000 

Boston. 


- 

73 

70,499 

Brooklyn. 



365 

•259,398 

Buffalo. 



225 

100 000 

Chicago. 



660 

150,000 

New York.. . . 



341 

535,709 

Philadelphia.. 



700 

266,831 

Washington... 



125 

127,623 

St. Louis. 



440 

200,000 
























HIGHWAY CONSTRUCTION". 


no 


G 


874. The relative amount of dirt produced by the different 
pavements, if swept daily, appears to be about as follows: 


Pavement. 

Cubic Yards per 1000 Yards 
of Surface. 

Asphalt. 

Wood (impervious joints). 

.007 to .04 
.04 “ .07 

“ (open joints). 

.07 “ .20 

Granite (impervious joints). 

.015 “ .024 

“ (open joints).... .. 

.07 “ .25 

Macadam. 

.10 “ .35 



These figures are only approximations and will vary with the 
amount of traffic,-state of the weather, and character of the pave¬ 
ment of intersecting streets: if these are productive of dirt, a large 
quantity will be dragged by the vehicles on to the good pavement, 
which is thus debited with a large quantity of material which does 
not rightfully belong to it. 

The care exercised in the removal of the ashes and garbage by 
the occupiers of the buildings on the street will also influence the 
amount of dirt to be removed. 

875. Methods employed for Cleansing. 

(1) By hand during the day. 

(2) By hand during the night. 

(3) By hand and machinery during the night, supplemented 
by a street orderly or patrol system during the day. 

Of the above methods each locality will have to decide upon 
the one which is best suited to its requirements. For large cities 
the third method is the most suitable. 

876. Systems of Executing the Work. 

(1) By contract; the contractor furnishing all the tools and 
labor. 

(2) By contract for the labor only, the city furnishing the tools 
and machinery. 

(3) By contract for the horses and removal and disposal of 
the refuse, the city furnishing the labor and machinery. 

(4) By the city, with its own staff and machinery. 

Cleansing by contract has generally proved unsatisfactory, from 

the difficulty of obtaining a proper observance of the terms of the 















MAINTENANCE.—REPAIRING ; CLEANSING ; WATERING. 527 

__I_ 

contract by the contractor and his employes, and it has been 
found that the work can be more carefully and systematically 
carried out by the civic authority with its own officers and staff. 
It is, perhaps, true that the work may be done under the contract 
system at less actual cost to the taxpayers, but all public work 
should be done in the best manner possible irrespective of cost, 
thoroughly, but without extravagance; and the result of such work, 
especially where it affects the cleanliness and the appearance of 
a town, soon fully repays any moderate extra cost that may thus 
have been incurred, irrespective of the enormous benefit that is 
conferred upon any community by the reduction of disease and 
the death rate by a proper attention to such necessary sanitary 
work. 

877. Cost of Cleaning.—The average cost of cleaning the dif¬ 
ferent pavements appears to be as follows: 


Asphalt. 

.003 cent per square yard per cleaning 

Stone block. ... 

.005 “ “ 

tt 

n a 

a 

Wood. 

.007 “ “ 

i c 

tt a 

tt 

Brick. 

.0034 “ “ 

n 

a a 

ti 

Broken stone. 

.0106 “ “ 

< t 

tt tt 

• 

11 


The average cost of supervision varies from .0L1 cent to 34 
cents per mile. 

The cost per mile of street cleansed varies as follows: 


Omaha, Neb. 

St. Louis, Mo. 

Boston, Mass. 

San Francisco, Cal 
Brooklyn, N. Y... 
Cleveland, Ohio... 


. 116.00 

. 17.00 

. 20.00 

. 20.75 

. 22.75 

22.90 to 70.00 


The amount annually expended per head of population in 
street cleaning is shown in the following table. It varies from 5 
cents in Buffalo and 8 cents in Chicago to 71 cents in New York 
and 92 cents in Cincinnati. 

The average of eleven bids for street cleaning recently received 
in Buffalo, N. Y., was for asphalt 37 cents per 10,000 square feet 
p er cleaning, for stone block 55 cents per 10,000 square feet pel- 

cleaning. 


















528 


HIGHWAY CONSTRUCTION. 


TABLE LXXXVII. 

Average Annual Cost per Head of Population for Street 

Maintenance. 


Cities. 

Average Cost per I 

Construction and 
Repairs of Streets. 

lead of Population. 

Street Cleaning. 

Baltimore, Md. 

$0.28 

$0.25 

Boston, Mass. 

1.84 

0.30 

Brooklyn, N. Y. 

0.49 

0.20 

Cambridge, Mass. 

0.64 

0.36 

Camden, N. J. 

0.38 

0.19 

Canton, Ohio. 

1.22 


Chicago, Ill.. 

3.18 

0.08 

Cincinnati, Ohio. 

2.88 

0.62 

Cleveland, Ohio. 

1.34 

0.19 

Dallas, Texas... 

0.47 

• • • • 

Davenport, Iowa. 

1.12 

0.19 

Detroit, Mich. 

1.63 

0.16 

Duluth, Minn. 

15.00 

0.15 

Elmira, N. Y. 

0.40 

0.07 

Evansville, lud. 

0.66 

0.15 

Fall River, Mass. . . 

0.89 


Hartford, Conn. 

0.88 

o.ii 

Hoboken, N. J. 

0.46 

0.05 

Lacrosse, Wis. 

0.81 


Lawrence, Mass. 

0.74 

6.07 

Lowell, Mass. 

1.27 

• • • • 

Lynn, Mass. 

0.72 

0.18 

Minneapolis, Minn. 

1.21 


Nashville, Tenn. 

1.71 


Newark, N. J. 

0.11 

0.16 

New Haven, Conn... 

1.68 

0.06 

New Orleans, La. 

0.14 

0.10 

Newport, Ky. 

0.60 

0.16 

New York, N. Y. 

0.68 

0.71 

Omaha, Neb. 

4.15 

0.16 

Philadelphia, Pa. 

0.61 

0.27 

Rochester, N. Y. 

1.06 

0.15 

Rockford, Ill... 

0.51 

0.08 

St. Louis, Mo. 

1.85 

0.28 

St. Paul, Minn. . 

5.69 

0.28 

San Francisco, Cal... 

Sioux City, Iowa. 

3.21 

0.20 

20.05 

0.16 

Springfield, Mass. 

■ • • • 

0.28 

Taunton, Mass. 

1.41 


Toledo, Ohio.. . 

4.03 

6.10 

Trenton, N. J. 

0.17 

0.03 

Washington, D. C.. 

2.50 

0.31 

Worcester, Mass. 

1.65 

0.08 



























































MAINTENANCE.—REPAIRING ; CLEANSING ; WATERING. 5^9 

878. The method of cleaning employed in Berlin, which is said 
to be the cleanest city in Europe, is as follows: 

The men are city employes. 

The sweeping-machines are city property, but the horses are 
hired by contract. 

The removal of sweepings is also done by contract; the con¬ 
tractors for this work being obliged to maintain suitable dumping- 
places, in return for which they receive for their free use the 
street sweepings. These sweepings are of some value, the con¬ 
tractors often realizing over $20,000 per annum from them. 

The contractors are bound under all circumstances to supply 
enough wagons to remove each day all street waste. The number 
of wagons required varies with the weather. In dry weather often 
hardly half so many wagons are needed as in wet weather. They 
are required to remove the rubbish as soon as it is swept up, and 
only in cases of bad weather are the sweepings allowed to stand more 
than one hour before being carted away. If these regulations are 
broken, the contractors forfeit a certain amount to the city. 

The streets are cleaned during the night. 

The number of men employed by the city is about 600, and the 
number of sweeping-machines in use in 1889 was 42. 

The area cleaned in 1889 was 3,361,312 square yards. 

The average daily amount cleaned by each man was 5716 
square yards. 

The area swept by a machine ranges from 6545 square yards on 
bad pavements to 10,315 square yards per hour on asphalt pave¬ 
ment. 

The total expenses of the street-cleaning department in 1888 
and 1889 were $481,493.48, made up of the following items: 


Wages. 

Uniforms. 

Tools, materials, etc 

Carting away. 

Sprinkling.. 

Depots for supplies.. 

Public closets. 

Miscellaneous. 


$193,261.44 

2.769.12 
44,819.76 

182,487.12 

53,110.56 

1 . 221.12 
1,279.44 
2,544.48 


$481,493.04 













530 


HIGHWAY CONSTRUCTION. 


Of this sum the street-car companies paid for cleaning and 
sprinkling the parts of the street occupied by their tracks the sum 
of $24,135.58. 

The quantity of refuse removed from the streets was as follows: 
In 1882-83, 95,493 wagon-loads; in 1888-89, 97,969 wagon-loads. 
The number of loads, therefore, varied very little in spite of the 
considerable increase of area cleaned. In fact in the year 1888-89 
the number was about 16,000 less than in 1878. when it amounted 
to 113,994 wagon-loads. This was due to the constant increase of 
good, impervious pavements. 

The wages of the laborers employed in the street-cleaning 
department vary between 36 and 83 cents per day, in addition to 
which they receive uniforms free. The salaries of inspectors range 
from $357 to $636 per year; they also receive their uniforms free. 

New employes after 1| years service are advanced to a higher 
grade. 

The men are paid for Sundays and holidays, and in case of 
sickness receive half-pay. Old workmen are pensioned after 10 to 
15 years’ service at $100 per year, and for 30 years or more $150. 
With relative allowance between, the number of pensioners in 1889 
was 11. Assistance is also rendered to sick employes. In 1889 
about $100 was expended for this purpose. 

879. In Paris street sweeping is performed by 2200 men, 950 
women, and 30 boys. They begin work at 3 a.m. in the summer 
and at 4 a.m. in the winter and continue without interruption till 
11, when the work for women ceases; the men continue for 10 
hours and are paid by the day from 65 to 74 cents. The women 
are paid 6 cents per hour and cannot earn more than 45 cents a 
day. All are obliged to provide their own- brooms. The roadmen 
in charge of the sweepers are paid from $21 to $25 a month. 
Those receiving the lower salaries are obliged each month to con¬ 
tribute the odd dollar to a reserve fund that is deposited to the 
credit of each workman until he quits his employment. The plant 
consists of upwards of 200 mechanical sweepers. 

The amount of refuse removed daily averages 2300 cubic yards 
and requires the daily use of 520 carts and 980 horses. The refuse 
is disposed of by public tender to contractors for a term of four 
years. 






MAINTENANCE.—REPAIRING ; CLEANSING ; WATERING. 531 


880. The cleansing of the city of London is carried out under 
the department of the commissioners of sewers. The force em¬ 
ployed consists of about 500 men, women, and children. The 
work begins at 8 p.m. and is concluded at 9 a.m. The street 
orderly boys begin work at 7.30 a.m. They number about 150, 
and their duty is to remove every particle of dirt, especially horse- 
droppings, in the area assigned to them before it has been ground 
by the wheels. Bins at the street curb receive the gatherings. Not 
only the more important streets, but minor ones, courts and alleys, 
are looked after by the orderly boys. These boys are lodged and 
fed by the city, a certain deduction for the purpose being made 
from their wages. As they reach manhood they are promoted to 
other positions, and when they attain old age, after faithful service, 
they are pensioned. 

The courts and alleys inhabited by the poorer classes are 
cleaned daily, and from May to October are washed with jet and 
hose usually twice a week. 

881. Baltimore, Md. —Population, 443,547. Street mileage 
cleaned (1891), 780. Total expenses of street-cleaning depart¬ 
ment, $283,070.54. 

Distribution of expenses: 


Collecting garbage.$139,062.16 

Cleaniug streets and removing dirt..... 118,423.00 

Dumps. 4,689.40 

Tools. 2,404.50 

Superintendence. 9,991.48 

Removing garbage from city (contract). 8,500.00 


$283,070.54 


The equipment consists of 150 garbage carts, 61 street-dirt 
carts, 136 scrapers and sweepers. Work executed by city employes. 
The wages paid range from $10 to $18 per week. The sale of 
street dirt and refuse realized $912.76. 

882. Boston. —Henry B. Wood, Executive Engineer of the 
street commissioners of the city of Boston, in a recent communica¬ 
tion to the daily press says: That modern hygiene calls for 
constant attention to the immediate removal of all kinds of street 
refuse from public highways and places before fermentation takes 













532 


HIGHWAY CONSTRUCTION. 


place, or disease-laden gases or dust, particles emanating therefrom 
can be disseminated. A mere occasional attempt to clear up what 
street litter we cannot climb over is not sufficient; indeed, the pave¬ 
ment must now be swept so clean that it is passable at any point 
for pedestrians. He continues: 

“ The number of miles of streets cleaned is 7273.24, at an average 
cost of less than $20 per mile, and the number of loads of street dirt 
removed is 77,000. The entire force of men employed has been 
about 300. Some streets have been swept every day, in sweeping 
weather; some three times a week. Each day’s work has been so 
assigned that the computed area covered per week has been figured 
up to about 590,000 square yards to a district. 

“ For a paved district of said area a good working gang is com¬ 
posed of one foreman, one sub-foreman, two sweeping-machine 
drivers, two water-cart drivers, sixteen sweepers, six teamsters, six 
helpers, and one dump inspector, allowing a trifle over one sweeper 
to" a mile of gutter-stroke. Such a force costs about $23,000 for a 
full year. Eighty-one per cent of the streets are either gravel or 
macadam, and the cost of cleaning averages about $65 per mile for 
each cleaning. 

“ The introduction of the push-cart patrol system as an important 
adjunct to the regular street-sweeping force has found approval 
in the tidy appearance of the business thoroughfares. It is 
found that, even after a street has been once thoroughly swept, in 
less than two hours’ time the sweeping of the sidewalks and the 
throwing away of waste material into the street will so disfigure its 
surface that it appears as though the street-cleaning force had 
neglected it in its daily rounds. To obviate this difficulty the 
push-cart patrol comes in, collecting and removing this refuse 
matter continually throughout the day.” 

In 1894 the average force employed was 303 men, using 3 three- 
horse machines, 19 double and 21 single sweeping-machines, 11 
water-carts, 90 street-carts, 100 horses, 14 asphalt-scrapers, and 
about 33 extra teams. The number of cart-loads of sweepings 
removed was 95,478, of which 30,766 loads were dumped at sea; 
10,433 miles of streets were cleaned and 2176 miles of paved gut¬ 
ters on macadamized streets. The average cost per mile, including 
supervision, labor, yard and stable expenses, was $15.61. The gross 
expenditure divided by the total mileage of streets in the city shows 




MAINTENANCE. — REPAIRING; CLEANSING; WATERING. 533 


that the cost per mile per season was $679. The operation of the 
push-cart patrol system was considered most satisfactory, and an 
extension of their routes is thought advisable. They alone took up 
50,280 barrel loads during the year. The cost of snow removal 
during the year was $78,382. 

883. Brooklyn, N. Y. —Population, 806,343. Street mileage 
cleaned, 380. Expenses of street-cleaning department, $239,875; 
supervision, $36,000. Work done by contract. Cost per mile, 
$22.75; cost per capita, 30 cents. 

884. Cleveland, Ohio.—Population, 261,456. Street mileage 
cleaned, 680. Expenses of cleaning department (1891), $116,- 
099.51. Work done by contract. Dry-weather cleaning, $22.90 
per mile; spring cleaning and scraping, $45.80 per mile; wet- 
weather cleaning, $70 per mile. Cost per capita, 42 cents. 

885. Detroit Mich. —The streets are cleaned when and as often 
as necessary. The work is done by day’s labor, with the aid of 
sweeping-machines. This work is principally performed by aged 
persons who cannot do a full day’s labor and cannot obtain work 
elsewhere. The purpose in employing labor of this character is to 
preserve the independence of the men and keep them from becom¬ 
ing paupers. Eight hours constitutes a day’s work, and $1.50 per 
day is paid. The hours and per diem allowance are fixed by the 
common council. 

886. In New York the street cleaning is executed by the 
municipal authority under the direction of a special bureau, part 
of the labor being furnished by men in its employ and part by con¬ 
tract; the carts are also furnished by contract. 

The total number of men employed ranges from 1500 to 2000, 
and the number of carts is between 300 and 400. The amount of 
sweeping collected per annum is about 550,000 cubic yards. The 
number of sweeping-machines employed is about 60. The number 
of miles of street swept each day is about 60, tri-weekly about 
200, and bi-weekly about 70. The refuse is deposited at sea, and it 
costs 18 cents per cubic yard to place it on the scoivs. 

The cost of cleaning the above street mileage, equal to an area 
of about 314,179,328 square yards, is about $1,279,647 per annum. 

887. Philadelphia, Pa.— Population, 1,046,252. Street mileage 
cleaned, 756. Work done by contract. Expense of street-cleaning 
•department, $552,000; supervision, $11,920. Ashes are removed 




534 


HIGHWAY CONSTRUCTION. 


weekly, garbage daily. Amount of refuse removed in 1891: garb¬ 
age, 84,005 loads; street dirt, 290,680 loads; ashes, 573,999 loads; 
dead animals, 14,795. Number of men employed, 400; number of 
machines, 17. The average number of miles cleaned per man was- 
118. 

888. St. Louis, Mo.—Streets paved with granite and wood swept 
by contract at 50 cents per 10,000 square feet per sweep. Asphalt 
pavements, 39 cents per 10,000 square feet per sweep. The mac¬ 
adam and Telford cleaned by hand labor, under the supervision 
of the street department. 

889. St. Paul, Minn.—Population, 133,156. Street mileage 
cleaned, 349. 

Total cost of cleaning by city force in 1891: 

Labor. Materials. 

Unpaved streets.$35,470.11 $119 11 

Paved streets... 20,296.27 1,121.32 

Total.$55,766.38 $1,240.43 

Cost of cleaning 30,000 square yards of asphalt pavement by 
hand under contract, $49.75 per week. 

Paved streets are scraped with hoes in the spring at a cost of 
about $35 per mile, and are afterwards kept clean with sweeping- 
machines at a cost of about $9 per mile. 

890. Washington, D. C.— The cleaning of the streets is at pres¬ 
ent performed by contract, at the rate of 33 cents per 1000 square 
yards for each sweeping. The improved alleys are cleaned under 
another contract at the same rate. The remainder of the work is 
done by hired labor, supplemented to some extent by men from the 
District workhouse. The extent of streets swept by the contractor 
is 3,102,026 square yards, equal to 126.37 miles. 

The remaining streets within the city, which are cleaned by 
hired labor and the chain-gangs, are as follows: 


Pavement. 

Square yards. 

Length, miles. 

Macadam. 

270,320 

8.0 

Gravel. 

591,418 

29.4 

Total. 

861,738 

37.4 

Unimproved.,. 

1,272,695 

71.9 




















535 


MAINTENANCE.—REPAIRING ; CLEANSING; WATERING. 

The contractor uses ten four-horse sweepers, five of the Wright 
and five of the Filbert pattern. The sweeping is done by night, 
except when the contrary is specifically authorized. 

The amount of material removed from the streets averages 1^- 
cubic yards per sweeping to every 3000 square yards of area swept. 
Before sweeping the route is sprinkled by the contractor at his own 
expense. The average force employed by the contractor, besides 
the 10 large sweepers, consists of 4 sprinkling-carts, from 40 to 50 
broom, hoe, and shovel men, and between 30 and 35 carts. The 
maximum force here named will clean 900,000 square yards of 
pavement in 12 hours. The total cost of the cleaning is divided 
between the government and the city, the cost per capita being 
about 21 cents per year. 

891. Street Orderly or Patrol System.—This system comprises a 
staff of men or boys usually the latter, equipped with a bag or scoop 
and a brush. Each boy is assigned to a definite area, from which 
he removes all horse-droppings and refuse as it falls and before it 
has time to be ground up by the wheels. The pans are of sheet-iron 
formed as shown in Fig. 281. The bags are of canvas and are shaped 
like an old-fashioned carpet-bag; one of the lips is provided with a 
metal edge over which the refuse is swept. The brush is generally 
made of a bundle of birch twigs. 

The refuse so collected is disposed of in different ways. 

In London cast-iron boxes are fixed at the curb into which the 
boys empty the scoops when filled; the receptacles are in turn 
emptied by shovels into carts at stated intervals. 

The bag is claimed to be better than the scoop; it holds more 
than the scoop, and therefore requires less running to the re¬ 
ceptacles to be emptied, and it covers up the refuse; but the empty¬ 
ing process is always troublesome and can hardly be conducted 
without considerable dirt being scattered in emptying. 

In Paris the refuse is collected in a similar manner, but instead 
of sidewalk receptacles they have a light wrought-iron vehicle pro¬ 
portioned to carry four full bags, two inside and two suspended 
from hooks on the outside. This system fills the bags at once, allows 
them to be stored without offence or dirt anywhere, and the final 
removal is expeditious and cleanly. Fig= 278 shows the hand¬ 
cart used by the street patrol in New York and several American 
cities. 







'5 30 


HIGHWAY CONSTKUCTION. 


892. Street cleansing is effected either by hand sweeping and 
scraping or by mechanical sweepers. As to which is the most 
economical, much depends upon the value of labor, and also upon 
the condition of the roads to he dealt with. On pavements covered 
with ruts and depressions machine brooms are not effective, but in 
point of time and as a general rule the value of a horse rotary¬ 
brush sweeping-machine is undoubted; the only time at which such 
a machine fails to do effective work is on the occasions when the 
mud to be removed (owing to a peculiar condition of the atmos¬ 
phere) has attained a semi-solidity, and is of a stiff and sticky con¬ 
sistency, when it either adheres to and clogs the brushes of the 
machine, or is flattened by them onto the road instead of being re¬ 
moved. In such a condition of the street the scraping-machine 
must be employed, but care must be exercised in its use, as there 
Is always danger of injuring the pavement. 

893. Cost of Street Sweeping.—City Engineer Rundlett has kept 
a careful account of sweeping the paved streets of St. Paul, by hand 
and by machines. The average cost by hand in May was $25.00; 
June, $20.18; July, $18.57. Total average per mile by hand, 
$20.00; by machine, $9.24. 

In cleaning the streets of St. Louis the bids for cleaning as¬ 
phalt pavements are 25 per cent below those based on granite 
block. 

In Washington the street cleaning costs from 29 to 35 cents a 
thousand yards, cleaned once. 

894. The amount of surface which one man can sweep per hour 
depends upon the condition of the pavement, dry, wet, or muddy. 
The following figures are approximate: 

Asphalt, dry. 

“ wet and muddy.. 

Granite block, dry. 

“ “ wet and muddy 

Macadam, dry. 

“ wet and muddy. 

895. The amount of surface cleaned by a mechanical sweeper 
will depend upon the width of the machine broom, the power of 
the horses, gradient, and condition of the surface. The wider the 
stioke of the broom the less will be the cost of sweeping. As the 


1200 square yards per hour. 


1000 “ 
1000 “ 
750 “ 

700 “ 

350 “ 


t < 

a 

< 6 

< i 

i i 

< ( 

it 

i i 

C i 

< ( 

it 

it 

i < 

a 

< t 










MAINTENANCE,—REPAIRING ; CLEANSING ; 


WATERING. 


537 


width of stroke differs in different machines, the area swept by each 
in a given time will vary with that width. 

The average speed of the mechanical sweepers is one and a 
half miles per hour. 

896. The cost of operating a machine sweeper is about 50 cents 
, per hour. With a machine having a stroke of 5| feet it will re¬ 
quire six strokes of the machine to sweep a 30-foot roadway; there¬ 
fore, to clean one mile of roadway 30 feet wide, such a machine 
must travel six miles, and will require about four hours and, at 50 
cents an hour, cost $2.00. With a machine having a stroke of 8 feet, 
but four miles' travel of the machine will be required. 

897. Brooms.—The hand brooms used are made of steel wire, 
rattan, bass and birch. As the strength and durability of these 
brooms is of some importance as affecting the ultimate cost of 
street sweeping, care should be exercised in their selection. 

Steel wire lasts longer than any other, but is only suitable for 
block pavements. Bass and birch are weak and speedily wear out. 
Rattan is most suitable for asphalt and Macadam pavements. 
Rubber squilgees or mops are most efficient for cleansing asphalt 
pavements. 

898. Carts and Wagons.—The carts and wagons employed in 
the removal of street dirt should be provided with covers. The 
employment of wooden carts for this work is not economical; the 
rough usage which they receive renders their life but a short one, 
and they are constantly requiring repair. Iron or steel should be 
substituted. Such carts are to be purchased in the market and 
have many points to recommend them. 

899. The methods employed for the final disposing of the street 
refuse are many and varied. In the seaboard cities and those situ¬ 
ated on rivers it is generally placed on barges, carried to sea or 
other deep water and deposited. In others it is used for filling in 
low lands (a practice which cannot be too strongly condemned). In 
a few localities it is destroyed by fire. This is the superior method 
and quite successful, and is gaining in favor in situations where 
difficulties are encountered in disposing of the refuse, the only ob¬ 
jection raised against it being the offensive odor. This odor is not 
so bad as people imagine; it approximates that of burning leather 
and can be entirely avoided by suitable devices and chimneys of 
sufficient height. As a rule, people are prejudiced against crema¬ 
tories being located near their residences. 






538 


HIGHWAY CONSTRUCTION. 


The cost of a plant for a town having a population of 100,000 
would be about $100,000. The cost of cremating the refuse ranges 
from 20 to 40 cents per ton, depending upon the amount of com¬ 
bustible the refuse contains. 

900. Removal of Snow.—An important feature of maintenance 
is that involved in the removal of snow. Good management im¬ 
plies that it shall be speedTy removed and not left to interrupt 
travel. 

901. In American cities no provision is made beforehand for 
the extra assistance required for its removal, and all that can be 
done is to collect as many teams and men as possible at the 
moment; the result is that much valuable time is wasted in this 
operation. In European cities, this extra labor is engaged in ad¬ 
vance. In Paris a contract is made each year with the general om¬ 
nibus company to supply carts and horses at any time needed. In 
London also, contingent contracts provide for any additional num¬ 
ber of teams required at a moments notice. 

902. The organization and arrangements for the removal of 
snow in the cities of Milan and Turin, Italy, are the most complete 
of any city, and a description of their methods may be interest¬ 
ing. 

The system adopted in Milan is as follows: The city is divided 
into districts of varying extent according to their importance; each 
district is allotted to a contractor, who has to find the carts, horses, 
and laborers, while the city furnishes the necessary implements, 
spades, shovels, brooms, scrapers, barrows, etc., with proper stipu¬ 
lations as to their care. The contracts are made annually, and gen¬ 
erally the same persons are anxious to secure them. The form of 
the contract is rigid, and the contractors, who are drawn from the 
trades most affected by winter—paviors, bricklayers, masons, quarry- 
men, etc.,—are held to a rigid responsibility. Payment is only 
made for work which is well done; slovenly and careless execution 
goes for nothing. The supervision of each district is under an en¬ 
gineer aided by assistants and the police. 

Payment is made per inch depth of snow fallen. The average 
depth of the snowfall in each district is determined from the depth 
of the snow caught on a number of stone posts fixed in open spaces 
and clear of shelter from buildings. Each post is capped with a flat 
slab set horizontally. The depth of the snow on these slabs is meas- 



MAINTENANCE.—REPAIRING ; CLEANSING ; WATERING. 539 


ured by the engineer of the district in presence of two of the con¬ 
tractors of his section. 

The average cost of removing the snow per inch of depth per 
square yard is .006 cent. Ordinarily the removal of the snow from 
the more active thoroughfares is finished within ten hours of the 
cessation of the storm, and from the rest within 24 hours, exclusive 
of night. 

The snow is dumped into the navigable canals and water-courses 
intersecting the city, and latterly into the new sewers in the central 
portions of the city, which are promptly flushed whenever it snows. 

The number of men engaged in the removal of snow in addition 
to the regular street-cleaning force, ranges from 2000 to 3000, 
according to the severity of the storm. The implements are housed 
in different storehouses throughout the city. The whole expense 
of removing and disposing of the snow during the remarkable 
winter of 1874-75, when more than 40 inches of snow fell, was about 
$44,000. In the case of each storm the work of removal was done 
within 24 hours. 

903. In Turin much the same method is practised, work being 
paid for by the exact measure of snow fallen. The street-car com¬ 
panies are obliged to bear their share of the expense, paying for a 
width of 9 feet 10 inches for single and 18 feet 8 inches for double 
tracks. 

904. Many schemes for the disposal of snow have been experi¬ 
mented with, such as dumping it into the sewers, melting it by 
the application of steam, hot air, etc., as also with salt; but the only 
successful scheme so far is by cartage, depositing it in adjacent 
streams, or where this is objectionable, as in the case of navigable 
rivers, it may be heaped up in vacant lots or in the squares and 
parks, provided no damage is done to the grass or paths. 

905. Dumping the snow down the manholes into the sewers has 
been tried in London and- other cities, but has generally failed 
through the snow consolidating. An experiment with this method 
in the city of Cologne gave the following results. A number of 
shafts were opened into the crown of the main sewer that empties 
into the Rhine, each shaft being from 2 to 5 feet square. At one 
of these places the sewer was of oval section, 6 feet X 4 feet, and 
the fall was 1: 600. It was possible to dump the snow directly from 
the carts, each of which held about two cubic yards, into the sewer 





540 


HIGHWAY CONSTRUCTION 


without stopping the flow there. At another place where the 
sewer was 4 feet X 2.3 feet and the same fall prevailed, this process 
was not possible although a strong stream of water was thrown on 
the mass from the water service-pipes. The large mass suddenly 
thrown into the sewer acted as a dam and had to be removed. 
But at this same shaft when the same amount of snow was regu¬ 
larly thrown into it by four laborers no stoppages occurred. A few 
hundred feet below the place all the snow was found to be melted. 
Several hundred loads of snow were removed through these two 
shafts alone in a few hours. 

The cost of melting snow by the application of hot air or steam 
far exceeds that of shovelling and carting away. 

906. In order to grapple with this question of the removal of 
snow when no provision has been made beforehand, the following 
suggestions may be of use: 

“It is useless to attempt to cart it away while falling, but try 
to make clear crossings for the foot-passengers and to keep the 
traffic open. If there should be a high wind at the time, and the 
snow drifts in consequence, cut through the drifts so as to allow 
the vehicular traffic to continue. • Directly the snow ceases to fall 
put on all available hands to clear the channel-gutters and street- 
gratings, in preparation for a sudden thaw, when, if these precau¬ 
tions were not taken, serious flooding and great damage to property 
might ensue; for the same reason cart away all the snow you can 
at the bottom of the gradients and in the valleys, and also from 
very narrow streets and passages, etc. In the wider streets use the 
snow-plough, or with gangs of men (in the snow season there is 
generally plenty of labor obtainable) shovel the snow into a long 
narrow heap on each side of the street, taking care to leave the 
channel gutters and gratings quite clear, and a sufficient space 
between the heaps for at least two lines of traffic. Passages must 
also be cut at frequent intervals through the heaps, in order to 
allow foot-passengers to cross the street, and also to let the water 
reach the channel-gutters as soon as the snow begins to melt.” 

907. With regard to the removal of snow from the footpaths, it 
is highly desirable that this should be effected by the occupiers of 
the premises adjacent to the street, as otherwise it adds immensely 
to the work of the local authority. The following interesting re¬ 
marks by the superintendent of the scavenging department of 
Liverpool will be no doubt read with great interest: 





MAINTENANCE.—REPAIRING ; CLEANSING ; WATERING. 541 


ihe only way to compass the removal of snow from the foot- 
walks of the principal thoroughfares within a comparatively short 
time is by sprinkling them with salt such as is commonly used for 
agricultural purposes. It is certain that, unaided by the salt, a 
sufficient number of men cannot be procured for the emergency of 
dealing snow fiom the footways of the most important thorough- 
faies. It has been stated by medical authorities that the applica¬ 
tion of salt to snow is detrimental to the health of people who have 
to walk through the ‘ slush 9 produced by the mixture, and that the 
excessive cooling of the air surrounding the places where the appli¬ 
cation has been made is injurious to delicate persons. It therefore 
seems that the application of salt to snow should not be undertaken 
during the daytime, but should be commenced not before 11 p.m., 
nor continued after 6 A.M., and that only such an area of footwalks 
should be so treated on any one night as the available staff of men 
can clear by an early hour the following morning.* 

“ To sweep snow from the footwalks whilst the fall of snow 
continues, and especially during business hours, appears to be 
wasteful and futile, and to apply salt during the same periods may 
be held to be injurious to health. 

“ That the snow of an ordinary fall can be removed from the 
footwalks by an application of salt an hour or so before they are 
scraped is an ascertained fact, except at least when a moderately 
severe frost has preceded, accompanied, or followed the snowfall, 
or when the snow has drifted into extensive accumulations. Were 
it not for the danger to health by excessive cooling of the air, and 
for the expense attending the operation, all the impervious pave¬ 
ments could be cleared of snow (unless the fall was a heavy one) in 
a comparatively short time by a liberal application of salt and the 
employment of the horse sweeping-machines as soon as the snow 
has become sufficiently softened to admit of their use. 

908. Weight of Snow.—Experiments made show that a cubic 
yard of fresh-fallen snow may weigh as much as 814 pounds or as 
little as 71, or a range of from 2.63 pounds to 30.14 pounds per 
cubic foot. 

“Snow readily compresses under traffic, and when removed 

* In New York and other American cities the use of salt for the speedy 
removal of snow is prohibited by ordinance, except on the switches of street 
railway tracks.—A. T.B. 









542 


HIGHWAY CONSTRUCTION. 


in carts and dumped elsewhere it may be assumed that on an 
average four cubic yards of snow measured as it has fallen is equal 
to one cubic yard when placed on the apparatus." This computa¬ 
tion, however, does not make any allowance for the snow thrown 
from off the roofs, etc., and it of course greatly consolidates whilst 
travelling in the cart. 

909. The removal of light falls of snow from country roads 
may be effected by the ordinary snow-plough forming it into a long 
narrow heap on each side, but taking care to leave the gutters un¬ 
obstructed. Heavy drifts must be cut through with the shovel. 

In some localities it may not be desirable to remove the snow, 
sleighs being used in place of wagons. In such cases care must be 
taken when a thaw sets in to have ditches and water-courses clear. 

910. Street Washing.—Cleansing the pavements by washing 
them with a stream of water from the fire-hydrants is practised in 
both Paris and London. In the former city it forms part of the 
daily routine, but in the latter it is only used periodically, and more 
especially in the courts and alleys. Disinfectants are also used in 
Paris in this connection. During 1890 this method was experi¬ 
mented with in New York. The results were not satisfactory; the 
muddy water collected in puddles in the hollows of the pavement, 
and the amount of mud and silt carried into the sewers threatened 
to soon choke them up. 

This method is specially applicable to impervious pavements, 
such as asphalt and stone blocks and brick with water-proof joints. 
\\ ood pavements when they become covered with sticky mud are 
more easily cleansed by washing. In washing asphalt the sludge 
formed should be removed by the use of rubber squilgees; their use 
will also hasten the drying of the surface.- 

911. Street Sprinkling.—Streets are sprinkled with water for the 
purpose of laying the dust and cooling the air. 

Two methods of applying the water are practised: (1) by hose 
attached to the fire-hydrants, and (2) by specially constructed carts. 

The carts are preferable to the hose method; with the latter 
there is less regular distribution of the water, and in some localities 
there may be pressure enough to cause injury to the pavements. 
Again, the hydrants are generally located so far apart that long- 
lengths of hose are required, and the constant rubbing soon wears 
them out. To obviate this metal pipe is employed in Paris; the 




MAINTENANCE.—REPAIRING ; CLEANSING; WATERING. 543 


pipes are usually iu lengths of 6.4 feet, mounted on two-wheeled 
trucks, and connected by flexible joints. 

Carts cause less interruption to traffic, require less time and 
fewer men; moreover, when there is a scarcity of water they may 
be filled from wells or rivers. 

912. Systems.— Three systems are practised for carrying out the 
work of sprinkling: (1) by the municipality, with its own equip¬ 
ment and men; (2) by contract, the contractor furnishing the labor 
and equipment; (3) by contract for the labor, the city furnishing 
the carts. The first system is generally the most satisfactory. 

913. Quantity of Water required. —The quantity of water re¬ 
quired will vary greatly, depending upon the character of the 
pavement and the temperature. The average number of gallons 
used in the United States per 100 square yards is 250; in Paris 
about 120 gallons per square yard; in London about 150 gallons. 

914. Frequency of Sprinkling. —The frequency of sprinkling 
will depend upon local circumstances. In Berlin all the streets 
are sprinkled twice a day from April 1st to October 1st, and the 
principal thoroughfares and squares are sprinkled three and four 
times per day in this period. For this work the contractor receives 
on an average $1.68 per day for each wagon. About 150 sprinkling- 
carts are used, each holding about 950 gallons. The street-car 
companies share the expense of sprinkling the streets occupied by 
their tracks. 

In American cities the frequency of sprinkling the streets varies 
with the locality and the seasons of the year. The general practice 
appears to be about as follows: 

Paved streets are sprinkled twice a day during the months of 
March, April, and November, three times a day during May and 
October, and four times a day during June, July, August, and Sep¬ 
tember. 

Unpaved, macadamized, and gravelled, streets are sprinkled 
twice a day during the months of March, April, May, October, and 
November, and three times a day during June, July, August, 
and September. 

It is not usual to sprinkle the streets on Sunday, but in some 
few localities boulevards and driveways used on that day are 
sprinkled once or twice. 

915. Cost of Sprinkling.— The cost of sprinkling is variable, de- 






544 


HIGHWAY CONSTRUCTION. 


pending upon the time occupied in travelling to and from the points 
where the water is obtained and where it is used. The range ap¬ 
pears to be from 4 mills to 7 cents per 1000 square yards sprinkled. 

In Indianapolis the average cost for sprinkling per lineal foot of 
street is 16.26 cents, and the average number of gallons of water 
used per square foot is 6.81. 

In St. Paul, Minn., during 1894, the price for street-sprinkling 
varied from $12.00 to $14.20 per mile per week. The sprinkling 
began April 26 and ended October 31. The cost per foot front to 
the property owners is from 4.75 to 5.3 cents for the entire season. 
These prices include the payment of $5.28 per mile per week to the 
water department for the water used. The average amount of 
water used was for July and August 15,100 gallons per mile per 
day. The average for the four months was 11,580 gallons per 
mile per day. 

916. Sea-water and deliquescent salts (as the chloride of calcium) 
have been used for street-sprinkling. The surface is kept moist, but 
at the expense of the moisture in the air, and it is said that horses’ 
hoofs are injured by the chemicals. 

In some cities during very hot weather disinfectants are mixed 
with the water used for sprinkling. The disinfectant usually em¬ 
ployed is a mixture of manganate of soda one pound, sulphuric 
acid half a pint, and water one gallon to every one hundred gal¬ 
lons of water used for sprinkling. 



CHAPTER XX. 


TREES. 

917. Opinions differ as to the desirability of trees on roads 
and streets. Some claim that they do more harm than good; 
that they impede the circulation of the air, and that, as far the 
shade they afford, people who do not like sunshine have only to 
keep on the shady side of the way; that they deprive the road-sur¬ 
face of the drying action of the sun and air, and that in wet weather 
the constant dropping of water from their branches keeps the road 
in a muddy state. Others claim that trees, especially in streets, 
temper the heat and serve as a protection against dust, that the 
evaporation from their leaves tends to keep the surrounding air cool 
and moist; that the perpetual vibration of their foliage and sway¬ 
ing of their branches, whilst admitting a sufficient amount of light, 
serve to protect the eyes from the noonday glare; that they act as 
disinfectants by drawing up and absorbing the organic matters con¬ 
tained in the filth from which the streets of a town are never 
free and which, infiltrating the ground, are a frequent cause of fevers, 
and infection; and it is asserted that on soil roads some varieties of 
trees both drain the road and help to hold its earthen surface to¬ 
gether by their root-fibres. 

“ Those who have observed woodland roads closely know they 
are dry except when below the general grade of the land or actually 
swamped with' water. At any point of temperature a tree, even in 
winter and without any leaves upon it, is evaporating moisture from 
its twigs, branches, and trunk. It must freeze very deep to prevent 
all root-action, and whatever moisture roadside trees may draw from 
the roadbed will, by so much, prevent the tendency to muddiness 
in any loam road well filled with tree-roots/’ 

“ Beside the draining and drying effect of tree-roots, the fibres 

545 


54G 


HIGHWAY CONSTRUCTION - . 


given to the soil by some kinds of trees (well known to ploughmen in 
all countries) have a most salutary effect in holding the earth to¬ 
gether. If the soil be rich, the whole substance of the raised and 
rounded roadbed may he completely filled with horizontal stitches, 
as the housewife darns and runs the heels of stockings, thus treb¬ 
ling their ability to resist friction. Roots in the surface-soil are 
better than brush to hold up travel when they are alive and pump¬ 
ing water out of the ground. If we are looking for economy, noth¬ 
ing can be cheaper than the way a maple, elm, cottonwood, or white 
pine will fill the surface of an earth road with fibre. The chestnut, 
hickory, ash, black walnut, and beach may all be thought of in this 
connection, but only the close student of nature and the variety of 
trees adapted to different soils and situations will succeed in this 
branch of road-making. Yet the nation has many thousand miles 
of muddy highway where no other improvement seems possible.” 

“ There is a use for the overhanging branches of trees in winter 
They shade the road and permit it to freeze or remain solid when, 
but for the shadow, the road would be softening in the sun. The 
branches work in this way to prevent and protect the road from 
being cut in pieces. The traveller and his weary team, swamped in 
thawed earthen roads, are glad to reach the frozen track on the 
north side of a bit of woodland. And the man who would cut away 
roadside shades so as to let all our earth roads thaw out and settle 
together is very much mistaken.” 

Trees also serve to make the border of the road discernible at 
night as well as after snowdrifts, thereby warning the travellers 
against embankments and other dangers along the sides of the road. 

918. In France, as far back as the middle of the sixteenth cen¬ 
tury, trees were planted along the royal roads. This practice has 
been more or less continuously followed. 

During several periods it was stopped by those in authority, 
they being of the opinion that trees were more of a damage than a 
benefit. But now trees are planted along all roads having a width 
greater than 10 metres (32.8 feet). They are placed at distances 
varying from 5 to 10 metres (16.4 to 32.8 feet), in single rows upon 
the narrow roads, and in double rows upon the wider. 

919. “The roads of Belgium are flanked on either side by two 
and sometimes four rows of shade-trees, which add much to the 
beauty of the country through which they run.” 




TREES. 


547 


920. Financial Value of Trees.—Take two streets in all respects 
alike, except that one has trees well selected, set at suitable dis¬ 
tances apart and well cared for, the other with no trees or with 
trees carelessly set and neglected, as frequently happens. A person 
wishing to purchase a residence will undoubtedly select the street 
having the fine trees, although he may have to pay more than many 
times the cost of the trees. Thus from a financial standpoint trees 

pay- 

921. In Saxony a considerable revenue is derived from fruit- 
trees planted on the roadsides. The trees are cared for by the 
roadmen in so far as professional knowledge is not required; they 
remove insects, clear the tree-frames of rubbish, and water 
them. 

In sections where fruit-trees cannot be cultivated on account of 
climatic causes, or where they would be liable to wanton damage 
and plundering of the fruit, forest-trees are planted. 

The state-road fruit-trees are leased to the highest bidders, and 
the money received is covered into the state treasury. The lessees 
of the fruit-trees are held to a strict account for any damage done 
the trees. Ladders must be used to gather the fruit, aud any 
battering of the trees with clubs or poles to get the fruit down is 
prohibited and is punishable by fine. 

922. Selection of Trees.—Trees should be selected with refer¬ 
ence to the climate, locality, quality of soil, extent of space, and 
circumstances of surroundings in general. 

Large-growing varieties should be selected for places of great 
extent, smaller varieties for places of less extent. A low compact 
tree is not suitable for street planting. 

The qualities necessary in a good street tree are that it must be 
hardy, must not be affected by a long-continued drought, heat must 
not wither it nor make it look rusty; it must be able to withstand 
dust, smoke, soot, foul air, and the insidious attacks of insects, and 
be able to recover from any malicious or accidental injury it may 
receive. 

The tree must be of rapid growth and develop a straight, clean 
stem with shady foliage. It must be graceful either in full leaf 
or when bare, as in winter; its roots must not require too much 
room, and they must be able to withstand the effects of pollution 
or rough treatment. 





548 


HIGHWAY CONSTRUCTION. 


As to wnat variety to select very little can be said; a largo 
quantity of suitable trees exists from which one may select as local 
conditions or fancy may dictate. 

923. Precautions to be taken in the Selection. —Whatever 
variety of tree is selected, the following precautions should be taken 
to insure its flourishing: 

(1) The young tree should have been well nourished in the 
nursery; it should not be planted on the street until its stem is 
over 8 feet in height and about 3 inches in diameter. The stem 
should be clean and straight, and the whole tree symmetrical. 

(2) The ground where a tree is to be set should be examined to 
see whether it is suitable for tree-growth. If it is not, the poor 
material should be removed and good soil substituted. The amount 
to be removed depends upon circumstances and can be determined 
by examination. A tree to flourish must have plenty of good 
ground in which to grow; it should be good to the depth of at 
least 3 feet, and an equal distance in all directions from the trunk 
when practicable. The amount of good soil is of greater importance 
than the shape it is in. The further the tree is planted from the 
curb the better, so as not only to give it a larger body of soil, but 
to lessen the risk of killing the tree by the pollution of the ground 
with gas from defective pipes and also excess of moisture from the 
gutters. 

924. Distance Apart to plant Trees generally appears to be a 
matter of choice, but this should not be so. Trees should be 
placed so far from one another that at maturity they will not meet. 
Such distances will enable them to develop in their natural beauty. 
To determine the proper distance apart measure the spread of full- 
grown trees of the same variety as those to be planted; it will vary 
from 30 to 50 feet. The trees should alternate on opposite sides of 
the street. 

925. Trees at Street-intersections. —Where streets cross at right 
angles or nearly so, two trees of large-growing varieties may be 
placed on each corner, far enough from the corner of the curb 
not to interfere with the catch-basin when there is one. Each 
tree should be placed on the tree line of one street and the fence 
line of the other; this will require eight trees to every intersection. 
The trees so planted should form a handsome mass of foliage and 
afford an agreeable shade where most needed. At some intersec- 




TREES. 


549 


lions it may not be possible to plant all the eight trees, but as 
many as can should be placed. 

926. Protection of Trees. —Each tree should be protected with 
a light iron railing to prevent mischievous persons from cutting 
their names no or otherwise injuring the trunk. 

Where it is necessary that the footpath be entirely paved the 
space around each tree may be arranged as shown in Fig. 177. A 
light stone curb is placed around the tree in a circle the diameter 
of which should be about 4 feet, and the curb should project above 
the pavement about 3 to 6 inches; this prevents people from walk¬ 
ing on the earth, keeps the ground from becoming hard, and 
permits air and water to enter to the roots. Or a cast-iron grating 
4 feet square may be employed for the same purpose. 




927. Specifications for Protection of Trees— The contractor 
when directed shall protect from injury trees upon the line of the 
work, and the grading around them must be carefully done. The 
grass sodding on the sidewalks must also be protected as much as 

possible. 






















CHAPTER XXL 


STAKING OUT THE WORK. 

928. The staking out of the work consists in placing stakes in 
the ground to direct the workmen and define the limits of the- 
work. 

The centre line of the proposed road is marked by stakes set 
(usually) at distances apart of 100 feet on the straight portions, 
and at 15, 25, or 30 or 50 feet on curves, depending upon their 
sharpness; on the stakes the cut or fill at that point is marked. 

929. The staking out of straight lines and simple curves of 
less than 100 feet radius presents no great difficulty; curves of 
greater radius, compound or reverse, will require to be set out by 
the same formula and methods as are empleyed for setting out the 
curves on railroads. For detailed instructions, etc., any one of the 
many railroad-engineer’s pocket-books may be used, such as Henck’s, 
Trautwine’s, or Shunk’s. 

930. Side Slopes. —The setting of the slope stakes on ground 
that is level or nearly so at right angles to the centre line is a sim¬ 
ple matter, the position of the stake being found by adding together 
the half-width of the roadway, and the base of the triangle ob¬ 
tained by multiplying the depth by the ratio of the slope. When 
the natural surface of the ground is inclined, the setting of the 
slope stakes is less simple. The ordinary method employed is a 
tentative process of combined levelling and calculation, which is 
nothing better than a rule of thumb. The manner of procedure ’ 
is as follows: Suppose it is desired to set the stakes D and E , Fig. 
178. The depth of the cutting at C is ascertained, and a point is 
taken on the surface where it is assumed the slope will cut; its 
height above AB is obtained; this height is multiplied by the ratio 
of the slope, and the half-width AC or CB added: if this agrees 
with the distance of the assumed point, that point may be taken as 

550 


STAKING OUT THE WORK. 


551 


correct; if not, a second trial must be made. A difference of 6 
inches will be of no practical importance. 



Fig. 178. MANNER OF SETTING SLOPE STAKES. 


The guessing may be aided by taking levels at the points F and 
G, and performing the calculations as outlined above. 

A more accurate and sometimes a more expeditious method is 
as follows: 

Take a cross-section book, and on each page plot the cross-sec¬ 
tion of the ground at each station, and draw the slope lines; the 
exact distances can then be obtained at a glance by counting the 
spaces between the centre line and the point where the side slope 
intersects the natural surface. 

Slope stakes are required at every centre stake along the line, 
and also where the ground is very rough at intermediate distances. 

931. Setting out Culverts. —The length of a culvert which 
passes under an embankment is less than the distance between the 
bottom of the opposite- side slopes, and may thus be found: From 
the height of the embankment H, Fig. 179, take the above ground 
height of the culvert h\ the remainder will be the height, h ,, of the 
embankment: then the required length ab is equal to the top width 
of the embankment cd, plus the width of the base of the slopes on 
the top of the culvert. Thus if CD equal 30 feet, and h 1 equal 5 
feet, the ratio of the slopes 1^ to 1, the length ab will be 

30 -f (5 X 3) = 30 + 15 = 45 feet. 










552 


HIGHWAY CONSTRUCTION. 


932. When the natural surface of the ground is horizontal, the 
length of any structure passing under an embankment will lie 

C D 



half on each side of the centre line. When the natural surface is 
inclined, the ends of the structure will be at different distances 



from the centre line, according to the slopes of the ground. This 
is seen in Figs. 180 and 181, the first of which represents the 
section, and the second the plan, of an embankment. The lines SS 





















STAKING OUT THE WORK. 


553 


and 00, representing the ends of a culvert passing beneath the 
embankment, are seen to be at different distances from the centre 
line. The position of the points S and 0 may be found by first 
getting from the tables of side width the points A and D, and 
measuring in from these points the distances and DO, de¬ 
pending upon the slopes AB and AD. In the case of the upper 
end the distance of SS from A will be less than if the natural sur¬ 
face was level; at the lower end the distance from D to 0 will be 
greater. Having found the distances of SS and 00 from the 
centre line, we get the position and length of the wing vralls of the 
culvert by drawing a line from S to any desired angle to intersect 
the slope A A ; and upon the lower side of the embankment we get, 
in the same manner, the lines DD, OD, the latter being of course 
longer than the wings upon the upper side AS, AS. 

933. Setting out Bridge Work. —In laying out the abutments 
for bridges there are numerous cases to be considered,—as whether 
the bridge is on the square or on the skew, upon a level or a 
gradient, upon a curve or a straight line, and whether the natural 
surface is horizontal or inclined; the position and form of abut¬ 
ments and wing walls depending so much upon the various condi¬ 
tions affecting each particular case, that any attempt to lay down 
general rules for each work would be of little use. 

934. Staking out Drains. —The method of setting grade marks 
for drains is as follows: 

At every 50 feet along the line of the trench place a board a 
couple of feet wider than the width of the trench, bed it firmly in 
the earth and mark the centre line on it; then ascertain the level 
of the boards, calculate depth of cutting at each one, and mark it 
idainly on each board. To transfer the grade line to the bottom 
of the trench, procure a measuring-rod (say 6 feet long), subtract 
the depth of cutting from the length of the rod, and to the board 
that straddles the ditch nail a piece of board upright, the height 
of which above the horizontal board is equal to the difference 
found. This operation being performed at each board, a line 
stretched from the upright pieces will be parallel to the grade line, 
and six feet above the bottom of the trench. 

935. Vertical Curves. —As stated in Article G10, the apex or 
meeting point of grades require to be rounded off by vertical 
curves, thus slightly changing the grade at and near the point of 




554 


HIGHWAY CONSTRUCTION. 


intersection. A vertical curve rarely need extend more than 200 
feet each way from that point (Fig. 182). 

Let AB, BC, he two grades in profile, intersecting at station B> 
and let A and 0 be the adjacent stations. It is required to join 
the grades by a vertical curve extending from A to C. Suppose a 


B 



chord drawn from A to C. The elevation of the middle point of 
the chord will be a mean of the elevations of grade at A and C, 
and one half of the difference between this and the elevation of 
grade at B will be the middle ordinate of the curve. Hence we 
have 

M= I ( g rade -A+ grade g _ grade B ), 

in which M equals the correction in grade for the point B. The 
correction for any other point is proportional to the square of its 
distance from A or C. Thus the correction at A -}- 25 is J/; 
at A + 50 it is i M; at A + 75 it is .M; and the same for cor¬ 
responding points on the other side of B. The corrections in the 
case shown are subtractive, since M is negative. They are additive 
when M is positive, and the curve concave upward. 

936. Staking out Contour of Street Foundations. —In order to 
insure the proper transverse form of street pavements, stakes 
should be driven across the street, the tops of which shall cor¬ 
respond to the intended contour. The stakes should be placed 
longitudinally of the street at distances not exceeding 16 feet, and 
transversely at distances not exceeding 10 feet. After the stakes 
are placed ridges of concrete may be formed along the street, as 
shown in Fig. 183. After the ridges or small banks of concrete are 







STAKING OUT THE WORK. 


555 


so placed the filling of the interspaces may be proceeded with, and 
a straight-edge resting on the ridges will guide the workmen in 
keeping the concrete to the proper form; or the stakes may be 
placed as directed above and a thin slat nailed to their tops, the 
concrete filled in and made flush with the top of the slat, a straight¬ 
edge 17 feet long, its ends resting on the slats, being used for this 



Fig. 183. MANNER OF FORMING CONTOUR OF 

STREETS. 

purpose. After the concrete is thoroughly set the slats may be 
removed and the space they occupied plastered over with cement. 

937. Setting Stakes for Curb. —Stakes for setting curb should be 
placed on the front line of the curb, with their tops at the required 
grade. Their distance apart should, not exceed 50 feet, and on cir¬ 
cular work will require to be closer. At street corners three stakes 
should be driven, one at the intersection point of the meeting curbs 
and one at each tangent point (Fig. 184). 



Fig 184. SHOWING MANNER OF SETTING STAKES FOR 

CURBS. 

938. In placing the stakes for any structure they should be 
placed so far outside of the work that they will remain undisturbed 
during the construction of the work. They must be so placed that 
lines stretched from any two of them will define the corner and 













556 


HIGHWAY construction - . 


face of the structure (Fig. 185). Stakes for defining the boundaries 
of an excavation may be placed at the angles thereof. 



Stake*--, . 

*5take 

FIG. 185. MANNER OF SETTING STAKES FOR STRUC¬ 
TURES. 


939. Two stakes, at a sufficient distance apart upon the land, 
w r ill fix any line upon the water; and two sets of stakes, upon 
different lines upon the shore, will by their intersection fix any 
point upon the water with accuracy sufficient for many purposes. 
For exact work, however, a transit should be employed to fix a line; 
and two angular instruments, in well-chosen positions, will deter¬ 
mine any point. 

940. Bench Marks. —A permanent bench or reference mark for 
levels should be established with care, in the immediate neighbor¬ 
hood of any proposed structure, from which the elevations of the 
various parts may be obtained. Such bench marks should also be 
fixed at the commencement of long cuttings, and generally at 
intervals of from 500 to 1000 feet along the works, a list of such 
elevations being entered in the engineer’s note-book. 





CHAPTER XXII. 


SPECIFICATIONS AND CONTRACTS. 

941. Specifications. —A specification or detailed description of 
the various works to be carried out is always attached to a contract, 
and is prepared before estimates are called for. The prominent 
points in connection with specifications are as follows: 

(1) Description of the work. 

(2) Extent of the work. 

(3) Quality of the materials. 

(4) Testing of the materials. 

(5) Delivery of materials. 

(6) Character of the workmanship. 

(7) Manner of executing the work. 

(8) Time of commencement. 

(9) Time of completion. 

(10) Manner and times of payment. 

(11) Penalties for infraction. 

(12) Such general instructions and stipulations as may be found 
necessary in each case. 

Attention to these points and a clear and accurate description 
of each detail (leaving nothing to be imagined) will not only 
materially contribute to the rapid and efficient execution of the 
work, but will avoid all future misunderstandings. 

942. Concerning Tests of Materials. —While proper tests should 
always be stipulated, yet if they are carried to an extreme degree, 
as frequently happens, they defeat their own object. When it be¬ 
comes impossible to carry out certain unreasonable demands, the 
alternative is to evade them as much as possible; and it must al¬ 
ways be borne in mind that the more stringent the demand, the 
greater the difficulty in enforcing it. 


557 


558 


HIGHWAY CONSTRUCTION - . 


943. Contracts.—A good, clear, and comprehensive contract is 
a difficult thing to write, but it should be “common-sense” from 
beginning to end, and should be the joint production of both en¬ 
gineering and legal ability, neither sacrificing the one feature to 
the other. 

GENERAL SPECIFICATIONS. 

The following specifications, in conjunction with those given 
throughout the work, will aid in preparing specifications for the 
different works connected with highways. 

944. Clearing. —The land will be cleared to the width of 

feet on each side of the centre line, and on each section must be 
entirely completed before grading is commenced. 

The clearing must be done in such manner that all useful 
timber may be saved. Trees of large dimensions shall be trimmed 
and put into the most profitable shape for the market; when so 
trimmed they shall be piled in such jfiaces along the line of the 
road as the engineer may designate. 

Brushwood, stumps, tree limbs, etc., must not be cast upon the 
adjacent land, but shall be formed into piles and burned; stumps 
and other material that will not burn, must be removed from the 
work and disposed of by the contractor. All brush or trees acci¬ 
dentally or otherwise thrown upon the adjacent lands must be 
taken off and disposed of as above described. The land when 
cleared must be left in a clean condition, and the contractor will 
be held responsible for all damage to crops, fences, fruit-trees, and 
timber of adjacent owners. 

945. Close Cutting. —Where embankments are to be formed more 
than one foot in height, the stumps shall be chopped close to the 
ground. 

946. Grubbing. —Where excavations do not exceed 2 feet in 
depth, or embankments one foot in height, all stumps shall be 
grubbed out. The catch-water drains, side ditches, and off-take 
drains shall be grubbed wherever required. 

947. Grading. —Grading will include all excavations and em¬ 
bankments required to form the roadway, all excavations and em¬ 
bankments required for altering the level of intersecting roads. 
Excavations for the foundations of all structures, excavations for 
all trenches and ditches, excavations required for the altering of 




SPECIFICATIONS AND CONTRACTS. 


559 


the channels of streams, etc., and all other excavations and em¬ 
bankments that may be required for the full completion of the 
road. 

The grading shall be executed in accordance with the lines and 
grades given by the engineer. The portions which are above grade 
are to be excavated, and such and so much of the excavated mate¬ 
rial as may be suitable for the purpose, and as may be necessary, 
shall be filled in those parts which are below the grade lines. The 
material excavated, not so used for filling, shall be placed in spoil- 
banks at such points as the engineer designates, or it may be re¬ 
moved from the line of the work by the contractor for his own use 
and benefit, if so directed. 

Where embankments are to be formed of a height less than 3 
feet, all top-soil and vegetable matter must be excavated to such 
depth as the engineer may direct. The material so excavated 
will be piled up outside of the embankment lines, and afterwards 
used to cover the slopes of embankments and cuttings; the surplus 
that remains after completing this work shall be removed and 
placed in spoil-banks at such places as will be designated by the 
engineer, or it may be removed by the contractor for his own use 
and benefit. In places where the embankments exceed 3 feet in 
height the perishable matter shall be removed, but no excavation 
done unless specially ordered by the engineer. 

All sloping ground covered with pasture shall be deeply 
ploughed over the base of the embankments before the latter are 
commenced. On slopes which have been covered with timber the 
slope shall be cut into stejis before the embankment is commenced 

948. Formation of Embankments.—Embankments of a heigh L 
less than 3 feet shall be made by horses and carts. Embankments 
of greater height may be formed by tipping from dump-cars travel¬ 
ling on a track. 

The embankments, will be formed to such height above the 
sub-grade as the engineer may direct, to provide for shrinkage, 
compressions, washing, and settlement, and they must be main¬ 
tained to the required height, width, and shape until accepted. 
Whenever embankments are made from side ditches, the width of 
the berm to be left at the foot of the slopes will be given by the 
engineer. 

In the formation of embankments no mud, muck, vegetable 




560 


HIGHWAY CONSTRUCTION. 


matter, tree stumps, or other materials which the engineer may 
deem unsuitable, will be allowed to be used. Such material must 
be removed from the line of the work and disposed of as the 
engineer may direct. 

After completion, the slopes of all cuttings and embankments 
will be covered to a depth of 6 inches with the loam and vegetable 
soil previously reserved for this purpose, or such shall be obtained 
from such places as the engineer may direct. 

The slopes of embankments will generally be 1| to 1, of earth 
excavations 2 to 1, of rock excavations 1 to 1; and no allowance for 
excavations outside the limits of these slopes will be made unless 
specially ordered by the engineer. 

The widths, slopes, and other dimensions may be varied at any 
time by the engineer to suit circumstances. 

In the event of slips occurring in excavations, the contractor 
will remove the debris and reslope the work. If the slips occur 
through carelessness on the part of the contractor, no allowance 
for the removal or reshaping will be made; but if they occur 
through unavoidable causes, he will be paid for it as loose rock or 
as earth, according to the class to which it may appear to the. 
engineer to belong. 

Rock shall be excavated to a depth of two feet below the sub¬ 
grade level and the space refilled with stone broken to a size not 
exceeding 2J inches. 

In the event of work being proceeded with in winter, no snow 
or ice will be placed in embankments or allowed to be covered up 
in them, and all frozen earth must be excluded from the heart of 
the embankment. 

949. Earth-work Measurement and Classification.—All earth¬ 
work shall be measured in excavation, and will be classified under 
the following heads, viz., earth, loose rock, solid rock. 

Earth will include clay, sand, gravel, loam, decomposed rock, 
and slate, stones and bowlders containing less than one cubic foot, 
and all other matters of an earthy nature, however compact they 
may be. 

Loose rock will include all bowlders and detached masses of 
rock measuring more than one cubic foot and less than one cubic 
yard; also hardpan, compact gravel, sandstone, and all other 
materials of a rock natuie (except solid rock) which may be 




SPECIFICATIONS AND CONTRACTS. 


561 


loosened with the pick, although blasting may be resorted to in 
order to exjiedite the work. 

Solid rock will include all rock found in place in ledges, and in 
masses or bowlders measuring more than one cubic yard, and which 
can only be removed by blasting, which fact will be determined by 
the engineer. 

950. Drains.—At such places as may be designated by the 
engineer, drains will be formed in the following manner: the 
trenches will be opened to the width and several depths given by 
the engineer. In the trenches so opened drains of tiles will be 
constructed, as directed by the engineer. 

The tiles furnished shall be the best quality of clay or terra¬ 
cotta, manufactured expressly for drainage purposes; they shall 
be in lengths of not less than one foot, and shall be of uniform 
diameter throughout. A pipe of larger diameter, broken in half, 
will be used for collars; the pipes will be laid true to grade and 
the trenches filled in with round field stones. The stones must 
not be thrown in, but shall be laid in carefully by hand, the largest 
stones being used to wedge the pipes in place; on top of the stone 
filling place good sods, with the grass side down. Silt-basins will 
be constructed of brick, of the forms and dimensions shown on 
plans, at the points designated by the engineer. 

951. Catch-water Ditches.—Catch-water ditches will be ex¬ 
cavated at the top of the slope of all excavations on the up-hill 
side only; they shall be excavated not closer than 6 feet to the 
edge of the slope; they shall be excavated on the lines and to the 
grades given by the engineer. 

952. Off-take Ditches.—These ditches will be excavated where- 
ever directed by the engineer, and will have such form and dimen¬ 
sions as he may direct. 

The contractor shall also excavate and form all other drains 
and ditches which the engineer may deem necessary for the proper 
drainage of the road. 

953. Rip-rap.—In cases where slopes require protection from 
the action of water, the protection works will be constructed of 
brush or stones, and will be carefully performed in such manner 
and of such dimensions as the engineer may direct. 

954. Retaining, Breast, Slope, and Parapet Walls.—These walls 







562 


HIGHWAY CONSTRUCTION. 


will be constructed at such places and in such manner as may be 
directed by the engineer. 

955. Culverts formed of earthenware, cast-iron pipe, stone laid 
dry or in mortar, will be constructed wherever directed by the en¬ 
gineer. Their form and dimensions shall correspond with the 
detailed plans prepared therefor. 

MASONRY. 

Stone masonry will be classified as follows : 

956. First-class Masonry shall be built of sound stone, of a quality 
to be approved by the engineer; it will consist of large rectangular 
stones, with the beds dressed parallel throughout, and the vertical 
sides hammer-dressed so as to form quarter-inch joints; the stones 
will be left quarry-faced except when otherwise ordered; rock-faced 
stones to have a one-inch chisel-draught cut on all four edges of the 
face, and no face projection greater than 3 inches. 

The rise of the courses of first-class masonry will not be less than 
12 inches, and may range up to 24 inches, the thinnest courses being 
invariably placed towards the top of the work; the stones in adja¬ 
cent courses shall break joints by at least one foot. 

Headers shall be built in every course not further apart than 6 
feet; they will have a length in the face of the wall of not less than 
24 inches, and they must run back at least 24 times their height; 
when they will not allow this proportion, they must pass through 
from front to back. Stretchers shall have a minimum length in the 
face of the wall of 30 inches, and their breadth of bed shall be at 
least 14 times their height. First-class masonry will be laid in 
Portland cement mortar, and each course must be thoroughly 
grouted before the next course is started. Each stone shall be 
■cleaned and dampened before being set. Improperly dressed stones 
must be recut before placing in the wall, as no hammering will be 
allowed after the stones are set. 

First-class masonry will include all dimension stone, such as 
coping, cap-stones, bridge seats, and parapets, abutments, and piers 
of large bridges. 

957. Second-class Masonry will include retaining-walls, abut-' 
ments, wing walls and parapets of minor bridges, and head walls on 
box culverts. It will consist of broken range-work, built of such 
stone as may be approved by the engineer; the stones shall be dressed 



SPECIFICATIONS AND CONTRACTS. 


563 


to horizontal beds and vertical joints; the face shall be “rock face,” 
with edges pitched to line, with no face projections exceeding 2 
inches. At least one third of the stones must be headers evenly 
distributed through the wall; the mortar joints shall not exceed one 
half-inch in thickness. All vertical joints must be broken by at 
least 6 inches. No stone will be allowed in the face of the wall 
which has a less area than 72 square inches. Quoin stones shall 
have a chisel-draught one inch wide cut on each side of the angle. 

The backing and foundation will be of large sound stones, 
roughly squared, no stone to measure less than 2 cubic feet. The 
broadest bed will be laid underneath, and must have a good bearing 
on the stones below. The stones shall be laid in full mortar beds, 
well bonded with each other and with the face stone, and with all 
spaces filled with small stones and spalls, well grouted. 

No stone shall be cut on the wall, and stones once bedded shall 
not be removed unless directed by the engineer. 

The foundation course shall be of large stones not less than 12 
inches in thickness and 8 feet area of bed, and when the wall is 4 
feet or less in thickness shall extend from front to back. 

The mortar employed for second-class masonry will be of Rosen- 
dale cement, in the proportion of 1 of cement to 2 of sand. Portland 
cement will be used wherever directed by the engineer. 

958. Third-class Masonry.—Masonry of this class will generally 
be used for box culverts, retaining and slope walls, and for back¬ 
ing for first-class masonry. It shall consist of sound stones laid on 
their natural beds, and roughly squared where used for face work. 

The walls shall be carried up in courses ranging from 15 to 18 
inches in height; each course shall be well bonded, having a header 
at every 3 feet. Not more than one third of the stones shall be less 
than 9 inches thick, or contain less than two cubic feet, and no 
stone shall be less than 6 inches thick. The stones shall be laid in 
Rosendale cement mortar, and each course well grouted. 

959. Fourth-class Masonry will consist of stone laid dry, and 
will be used for box culverts, retaining, slope, breast, and parapet 
walls, and paving of box and arch culverts. 

960. First-class Arch-culverts shall be built in accordance with 
the specifications for first-class masonry, with the exception of the 
arch sheeting and ring-stones. The ring-stones shall be so dressed 
that when laid their beds will radiate truly from the centre of the 
circle. The ring-stones and sheeting shall not be of less thickness 




564 


HIGHWAY CONSTRUCTION - . 


than 10 inches on the soffit, and shall he dressed the full depth of 
the bed, so as to form joints not exceeding three eighths of an inch; 
each stone must break joints with its fellow by at least 10 inches. 
Arch stones to be full bedded in mortar, and each course afterwards 
thoroughly grouted. The face stones to be rock-face, with a one- 
inch chisel-draught around the edges. 

961. Second-class Arch-culverts.—Arch-culverts of 8 feet s]!an 
and under shall be constructed of suitable flat bedded stones, rang¬ 
ing, according to the span, from 16 to 24 inches dee]!, and with a 
minimum length of from 16 to 24 inches, and 5 to 6 inches in 
thickness on the soffit. They must invariably extend through the 
entire thickness of the arch; each stone to be well and closety fitted 
so as to give half-inch joints, and to break joints with its fellow 9 
to 7 inches. The whole to be laid in thin cement mortars, and each 
course well grouted immediately after being laid. 

The face-stones of the arch to be as nearly uniform in depth as 
possible, of large size, and neatly incorporated with the perpendicu¬ 
lar face of the masonry. The keystones to be 10 or 12 inches on 
the soffit, to have a chisel-draught around their edges, and to project 
beyond the face of the wall 2 or 3 inches. The side and wing walls 
will be of second-class masonry. 

The extrados of all arches shall be flushed with cement mortar 
three inches thick, levelled up and rounded to a moderately even 
and smooth surface. 

962. Centring.—Centres of arches must in all cases be well 
formed, of ample strength, securely placed in position, and in every 
respect conform to the requirements of the engineer. The ribs 
must not be placed further apart than 3 feet in any case. The 
lagging shall be 3 inches thick; the supports of centres shall be 
substantial and well constructed, and they must be provided with 
proper wedges for easing centres when required. Centres shall not 
be struck without permission from the engineer. 

963. Wing Walls will generally be of first-class masonry, laid 
up in steps, each step covered with a hammer-dressed coping. 

964. Parapets of masonry structures will be of first-class ma¬ 
sonry, covered with hammer-dressed coping. 

965. Laying Masonry in Freezing Weather.—No masonry is to 
be built in freezing weather, except by permission of the engineer. 
If such permission is given the mortar shall be made by either of 
the following methods: 



SPECIFICATIONS AND CONTRACTS. 


565 


Make a mortar of one part of hydraulic lime and three parts of 
sand, mix thoroughly, and allow it to stand in a heap covered with 
stable manure until used, to prevent freezing. 

Mix mortar for use with ordinary cement in the proportions 
of one to three. Both mortars to be saturated with brine in the 
final mixing. Or, 

Dissolve one pound of rock salt in 18 gallons of water when the 
temperature is at 32 degrees Fahr., and add one ounce of salt 
for every degree lower of temperature, or enough salt, whatever the 
temperature may be, to prevent the mortar freezing. 

No masonry laid in freezing weather to be pointed until 
spring. 

966. Pointing.—All outside joints of first- and second-class 
masonry shall be raked out to a depth of one inch, and neatly 
pointed with a mortar made of one part Portland cement and one 
part of sand. 

967. Grouting.—Each course of masonry as laid shall be grouted 
with a mixture of two parts of cement to 3 parts of sand, no more 
water being used than that necessary to give the required fluidity. 

968. Brick Masonry.—The bricks used shall be of the best 
quality, hard-burned entirely through, regular and uniform in 
shape and size. Soft or underburned bricks will not be allowed in 
the work. The bricks shall be laid in cement mortar made as 
directed. Every brick shall be laid in a full bed of mortar on bot¬ 
tom, sides, and ends, which for each brick is to be performed at one 
operation. In no case is the joint to be made by working in mortar 
after the brick is laid. The joints shall not exceed f of an inch, 
and none shall be less than i of an inch, and shall be neatly struck 
or flush-pointed. Every sixth course to be headers. No “ bats ” 
shall be used except in the backing of walls, where a moderate 
proportion (to be determined by the engineer) may be used, but 
nothing smaller than half-bricks will be allowed. 

The bricks will be inspected and culled on delivery, and those 
condemned must be at once removed. 

The bricks must be thoroughly wet just before laying. 

In forming arches the bricks must be laid in concentric rings, 
each longitudinal line of bricks breaking joints with the adjoining 
lines in the same ring and in the ring under it. 

969. Dry Walls.—Retaining, slope, parapet, and breast walls of 



5G6 


HIGHWAY CONSTRUCTION. 


dry stone will be constructed where directed. The stones for this 
class of work must be sound, flat, bedded stones. No round or 
cobble stones will be allowed. Not more than one third of the 
stones shall be less than one foot thick, and no stone shall be less 
than six inches thick or have a bed area of less than four feet. The 
stones shall be set horizontally on their largest bed, and so well 
bedded and fitted as to require neither spalls nor wedges to keep 
them in place. All walls shall be covered with a hammer-dressed 
coping of the dimensions shown on the plans. 

970. Dry Box-culverts.—The bottom shall be paved with good 
sound stone closely set on edge under the walls as well as the water¬ 
way. The side walls shall be built of large well-shaped stones well 
bonded and joints well broken. No stone shall have a less area 
of face than one square foot. There shall be one header to every 
three stretchers, and the header must pass entirely through the 
wall. The covering-stones must be entirely sound and wide enough 
to extend at least two thirds across either wall. 

The end walls of box-culverts shall be laid up in second-class 
masonry and finished off in accordance with the plans. The coping 
must be of proper and uniform thickness, neatly hammer-dressed on 
top and face. 

971. Pipe-culverts.—Culverts of salt-glazed earthenware or 
cast-iron pipe shall be constructed at such points as the engineer 
may designate. The ends of said pipes will be carried by head 
walls of either brick or stone masonry covered with stone coping. 
The form and dimensions of these structures shall correspond to 
the plans prepared therefor. 

The earthenware pipe shall be of the quality known as culvert- 
pipe. It shall be sound and well burned throughout, free from 
cracks, flaws, fire-checks, and other imperfections, and shall be of 
uniform thickness throughout and shall have not less than the 
following weights: 


Internal diameter. 

6 inches.... .. 

9 “ . 

Weight per foot. 

12 

<i 

. 40 

t ( 

15 

( i 

. 60 

ti 

18 

(t 

. 80 

< < 

20 

it 


i i 

24 

i ( 


it 

i 










SPECIFICATIONS AND CONTRACTS. 


507 


The joints shall be closed with cement-mortar. 

Cast-iron pipe shall be used wherever directed by the engineer, 
and shall be obtained from a foundry approved by him. It shall 
be of the diameters and thickness ordered, will be laid in the same 
manner as earthenware pipe, and the joints calked with lead if so 
ordered. 

972. Cement.—All cement furnished must be of some well and 
favorably known brand, and shall be approved by the engineer. It 
shall be delivered in barrels or equally tight and safe receptacles, 
and after delivery must be protected from the weather by storing in 
a tight building or by suitable covering. The packages shall not be 
laid directly on the ground, but shall be laid on boards raised a few 
inches from it. To insure its good quality it shall be subjected to 
the following tests, and every cask or lot of cement rejected by the 
engineer shall be conspicuously marked “ condemned,” and shall be 
removed from the site of the works; and, after rejection, should any 
of the cement so rejected be found to have been used, the work 
where it has been used shall be taken down and replaced with 
cement of the proper quality without extra compensation. 

The supply of cement must be so gauged that a sufficient quan¬ 
tity will be kept on hand to allow ample time for the tests to be 
made without delay to the work of construction. 

973. Cement Tests.—The Rosendale cement must stand a tensile 
strain of 50 pounds per square inch of sectional area on specimens 
mixed to a stiff paste and allowed to set thirty minutes in air and 
twenty-four hours under water, and of 90 pounds on specimens 
allowed to set seven days under water, and shall be ninety per cent 
fine when tried with a sieve having 2500 meshes to the square inch. 
It must take not less than twenty-five minutes to bear the light 
wire, that is, a weight of four ounces on a wire one twelfth of an 
inch in diameter. • 

Portland cement shall be tested in the same manner and the 
requirements for fineness will be the same, but specimen briquettes 
will be required to resist without fracture a tensile strain of at 
least 175 lbs. per square inch at the expiration of three days, and at 
the expiration of seven days to show an increase of at least 50 per 
cent over the strength at three days, but it must bear a minimum 
strain of 350 lbs. per square inch at the end of seven days. 

974. Sand.—The sand used for making mortar shall be sharp, 




568 


HIGHWAY CONSTRUCTION. 


clean, and free from loam and vegetable matter. If sand of the 
required quality cannot be found in natural beds on the line of the 
work, it shall be furnished by the contractor. The sand shall be 
screened and washed if so ordered by the engineer. 

975. Water.—The water employed for mortar shall be fresh and 
clean, free from mud or other objectionable matter. Sea-water 
may be used if permission is given by the engineer. 

976. Mortar shall be composed of two parts of sand and one 
part of cement, mixed thoroughly dry and tempered to the required 
consistency. 

When Used .—It shall be used as soon as made, and any mortar 
that may have taken a “ set” while unused shall be wasted. 

Variation in Proportion .—No variation from the above propor¬ 
tions will be permitted unless to make the mortar richer when 
required in special cases. 

Tempering .—The thorough mixing and incorporation of the 
materials will be insisted upon. The dry cement and sand shall be 
turned over and mixed with shovels by skilled workmen not less 
than ten (10) times before the water is added; after adding the water, 
the paste shall be again turned over a d mixed by skilled workmen 
not less than six (6) times before it is used. 

Boxes .—Tight mortar boxes will be provided, and no mortar 
shall be made except in such boxes. 

977. Concrete, how Composed.—Concrete shall consist of angular 
fragments of sound, durable stone or hard-burnt brick, which shall 
be cleaned and thoroughly freed from dust and dirt, and broken so 
as to pass in any direction through a ring two (2) inches in diameter, 
and of hydraulic cement and sand, in the following proportions by 
volume: 


Cement. ... 1 part 

Broken stone. : :. 5 parts 

Sand. ... 2 “ 


Mixing .—These materials shall be intimately incorporated on 
the mixing-board or in a mechanical mixer, and after proper tem¬ 
pering shall be deposited carefully in place and thoroughly rammed 
until the surface is floated. 

Period of Repose .—The concrete so laid shall be left without 
disturbance or shock for at least twenty-four (24) hours. 







SPECIFICATION'S AND CONTRACTS. 


560 


Variation in Proportions. —The above proportions shall be 
varied without extra compensation upon the order of the engineer 
and to his entire satisfaction. 

Expeditious Operation. —The whole operation of mixing and 
laying each batch of concrete shall be performed as expeditiously 
as possible, with the use of a sufficient number of skilled men. 

978. Foundation Excavation.—Foundation-pits shall be ex¬ 
cavated to such depths as the engineer may deem proper for the 
safety and permanence of the structure to be erected. 

979. Artificial Foundations.—Foundations of piles, timber, 
plank, and concrete shall be prepared of such dimensions and in 
such manner as the engineer may direct, and the materials used 
shall conform in quality, etc., to the requirements stated for the 
respective kinds. 

980. Timber.—The timber furnished shall be sound, straight- 
grained, well seasoned, and free from sap, large knots, shakes, and 
wanes. Knotty timber will not be allowed in the work where such 
would impair its strength. 

981. Piles.—The piles shall be of sound, straight-grained tim¬ 
ber from which the bark has been removed; they shall measure 
not less than 8 inches in diameter at the small end, nor be less 
than 28 feet long. They may be driven with any approved form of 
pile-driver or by the “ hydraulic jetif they are driven by this 
latter method, they shall be constantly loaded with a weight of 
2000 lbs. They shall be driven, by whichever method adopted, 

until thev do not move more than one-half inch under the blow of 

%} 

a hammer weighing 2000 lbs. and falling 30 feet. 

982. Cofferdams.—Where cofferdams are required for founda¬ 
tions, they shall be constructed in the manner directed by the 
engineer, and all puj&ping, bailing, and draining shall be performed 
as required and di™w.'by the engineer. 

983. Wrought-iroC—All wrought-iron work furnished to be of 
the specified form and dimensions. The wrought-iron used shall 
be the best refined iron; it shall be tough, close-grained, highly 
fibrous, and when broken shall show a blue-gray fracture. It shall 
bear a high welding heat, and a cold bar must bend through 90 de¬ 
grees without sign of fracture; the tensile strength to be not less 
than 50,000 lbs. per square inch of sectional area when tested in large 
and long lengths. The reduction of breaking area shall average 25 





570 


HIGHWAY CONSTRUCTION - . 


per cent, and the elongation of the bar before rupture shall be at 
least 15 per cent. Iron subjected to compressive strain to have an 
elastic limit of not less than 25,000 lbs. per square inch. 

984. Cast-iron.—All cast-iron work to be of the specified form 
and dimensions; the iron to be gray iron, of uniform color and 
structure, with medium grain, sharp bright fracture, tough texture, 
and a low percentage of graphite. It shall be clean and free from 
sand, scoria, cold-shuts, blow-holes, blisters, or other injurious de¬ 
fects. Sample pieces 1 inch square, cast from the same heat of 
metal in sand-moulds, shall be capable of sustaining, on a clear span 
of 4 feet 8 inches, a central load of 500 pounds when tested in a 
rough bar. A blow from a 4-pound hand hammer shall produce an 
indentation on a rectangular edge of the casting without flaking 
the metal. 

GENERAL STIPULATIONS APPLICABLE TO ALL CONTRACTS. 

The following stipulations are applicable to all classes of work 
and should be inserted in all specifications, being varied, of course, 
to suit each particular case. 

985. Interpretation of Specifications.—In case of ambiguity of 
expression in the specifications, or doubt as to the correct interpre¬ 
tation of the same, the matter shall be submitted to the engineer, 
whose decision shall he final. 

986. Omissions in Specifications.—Any work or materials that 
may have been accidentally omitted in the description of the work, 
but which is clearly implied, shall be furnished by the contractor 
the same as if it had been specifically stated. 

987. Engineer defined.—Wherever the word “engineer” is used 
it refers to the chief engineer or his authorized assistants, by whom 
all explanations and directions necessary for the satisfactory pros¬ 
ecution and completion of the work described in these specifica¬ 
tions will be given. 

988. Contractor defined.—Wherever the word “ contractor ” is 

used it refers to and means the party or parties who shall have duly 
entered into contract with the of to perform 

the work; their duly authorized agents or legal representatives. 

989. Notice to Contractor.—Any written notice to the contractor 
which may be requisite under these specifications may be served on 




SPECIFICATIONS AND CONTRACTS. 


571 


said contractor either personally or by mail, or by leaving the same 
at bis last known place of residence. 

990. Preservation of Engineer’s Marks, etc.—All engineer’s 
marks and stakes after location shall be carefully preserved with¬ 
out disturbance until permission for their removal or erasure shall 
be given, and every facility must be furnished for the staking out, 
etc., of all work to be done under these specifications. 

991. Dismissal of Incompetent Persons.—Any incompetent per¬ 
son or persons who may be employed on the work shall be removed 
on the requisition of the engineer; and no person so removed shall 
thereafter be employed upon any portion of the work. 

992. Spirituous Liquors.—Contractors are not to give or sell or 
suffer any one to give or sell or keep any ardent spirits on any part 
of the work or in any boarding-house or building under his control. 

993. duality of Materials.—All materials furnished and used 
under these specifications must be of the best quality of their re¬ 
spective kinds, free from any and all defects which in the judg¬ 
ment of the engineer may render them unfit for use. Rejected 
material must be at once removed from the works or con¬ 
spicuously marked “ condemned.” If condemned material is used 
in any part of the work, the same shall be removed and replaced 
with materials of the quality required by these specifications. 

994. Samples.—Before any materials are used, samples thereof 
shall be furnished the engineer by the contractor. Said samples, if 
approved, shall remain in the engineer’s office and be used as the 
standard with which all like materials furnished under these speci¬ 
fications must agree. 

995. Deviations from Plans and Specifications.—No deviations 
from the specifications or detailed plans will be allowed, unless a 
written permission shall have been previously obtained from the 
engineer. 

996. Right reserved to alter Details.—The engineer, during 
the progress of the work, may, by giving written notice to the con¬ 
tractor, alter any of the details of construction in any manner that 
may be found expedient or suitable; such alterations shall not in¬ 
validate the contract, and the contractor must adopt and execute 
the same as if they were part of the original contract, and at the 
completion of the work an allowance will be made for such alter¬ 
ations, etc., either for or against the contractor as the case may be, 
and the value of such alterations will be estimated by the engineer 






572 


HIGHWAY CONSTRUCTION. 


from the schedule of prices attached to the contract, or should it 
not apply, the equitable amount will be estimated by the engineer. 

997. Inspectors.—The work under these specifications is to be 
prosecuted at and from as many different points on the line of the 
work as the engineer may from time to time determine, and at each 
of said points inspectors may be placed on the day designated for 
the commencement of the work thereat. Whenever any work is In 
progress at or from one or more points at a time, an inspector may 
be appointed by the engineer to supervise each subdivision of tho 
same, viz., for the inspection of the material, excavation, prepara¬ 
tion for the foundation, the laying of the pavement, etc. 

998. Defective Work.—The contractor will be held responsible 
for the faithful execution of the work in accordance with the speci¬ 
fications. Any defective work that may be discovered by the engineer 
or his appointees before the final acceptance, or before final jiav- 
ment shall have been made, shall be removed and replaced by work 
and materials which shall conform to the spirit of the specifica¬ 
tions; the fact that the inspector or other person in charge may 
have overlooked such defective work shall not constitute an ac¬ 
ceptance of the same. 

999. Measurements.—The different classes of work will be 
measured as follows: 

Clearing and grubbing by the acre. 

Excavation in all classes of earth, rock, etc., and in all situations, 
including ditches, foundations, altering the channel of water¬ 
courses, borrow-pits, etc., by the cubic yard; the measurement 
shall invariably be made in excavation. If any case should arise 
where this may be found impossible, then the engineer shall deter- 
mine the quantities, making all proper allowances, of which he wi!3 
be the judge. 

Overhaul .—The contract price of excavation shall be takeai to 
include the whole cost of hauling, except only extreme cases which 
may involve a haul of more than eight hundred (800) feel For 
every hundred feet over eight hundred (800) and up to tweaty-^ve 
hundred (2500) the contractor will be allowed at the rate of one 
cent per cubic yard; that is to say, in the event of the haul being 
in any case 2500 feet, seventeen cents (17) per yard will be added 
to the schedule rate, and will be the maximum allowance for over¬ 
haul in any case.. 



SPECIFICATIONS AND CONTRACTS. 


57S 


The price stipulated for excavation of the several denominations, 
together with the price of overhaul in extreme cases, shall be the 
total price for excavating, loading, removing, depositing, and shap¬ 
ing ail the material. In a word, the rates and prices stipulated in 
the contract must be understood to cover every contingency,—the 
furnishing of all labor, material, power, and plant, the cost of finish¬ 
ing up cuttings and embankments, the dressing and draining of 
borrow-pits, and the dressing of slopes to the required angle, and 
the completing of everything connected with the grading in a 
creditable and workmanlike manner, in accordance with the direc¬ 
tions and to the satisfaction of the engineer. 

Masonry of all kinds and classes (stone and brick) by the cubic 
yard in place. 

Timber, lumber and plank, of all kinds and for all purposes, by 
the foot, board measure, in place. 

Piles by the lineal foot in place. 

Culvert and Drain-pipe of all classes by the lineal foot in 
place. 

Stone, Erich, and Pole Drains by the lineal foot in place. 

Concrete by the cubic yard in place. 

Curbing by the lineal foot in place. 

Gutters by the square foot in place. 

Crossing or Bridge Stones by the square foot in place. 

Catch-basins by number as completed, including all appurte¬ 
nances and connections. 

Bridges by the lineal foot in place. 

Pavements .—All classes of pavements will be measured by the 
square yard in place; and the area occupied by the rails oi street 
railways will be deducted, but the space occupied by manhole 
heads and catch-basins, when not exceeding one square yard each, 
will be included. 

The several measurements will be made and computed by the 
engineer, and his final return of the several amounts shall be the 
only valid account of the work done and materials furnished. All 
previous estimates upon which partial payments may have been 
made are merely approximate, and subject to the collection of the 

final return. 

1000. Partial Payments.—Monthly estimates shall be made 
during the progress of the work, and payments to the amount of 80 



HIGHWAY CONSTRUCTION - . 


574 

per cent thereof will be made, the retained percentage not being 
due or payable until the final completion of the work. These 
monthly estimates do not constitute an acceptance of the w r ork, 
the final estimate and formal acceptance constituting the only 
valid acceptance of the whole or any part of the work. 

1001. Commencement of the Work.—The work to be done under 
these specifications shall be commenced on such day and at such 
place or places as the engineer may direct. Failure to so commence 
without a good and valid reason therefor will be authority for the 

to declare the contract forfeited, and the said may 

proceed with the execution of the work in such manner as may be 
deemed proper. 

1002. Time of Completion.—The work shall be prosecuted in 

such manner as to complete it in accordance with the specifications 
on or before the expiration of working days. Should the 

execution of the work be delayed in consequence of any act or 
omission on the part of the , the condition of the weather, 

or by any circumstances so unusual that they could not be foreseen 
previous to or avoided during the construction of the work (all of 
which shall be determined by the engineer, who shall certify the 
same in writing), the time during which the work was so suspended 
shall be excluded, and the time extended by a corresponding 
number of days. 

But neither an extension of time for any reason beyond the 
date fixed for the completion of the work, nor the acceptance of any 
part of the work comprised in these specifications subsequent to 
the said date, shall be deemed to be a waiver by the said 
of the right to abrogate the contract for abandonment or delay in 
the manner herein provided. 

1003. Progress of Work and Forfeiture of Contract. — The 

reserves the right to declare the contract forfeited, if at 
any time it should appear to the engineer that the work or any part 
thereof is being unnecessarily delayed, or that the contractor is 
wilfully violating any of the conditions of the contract, or is exe¬ 
cuting the same in bad faith, or if the said work be not fully com¬ 
pleted within the time named for its completion; he shall have 
power to notify the contractor to discontinue all work or any part 
thereof, by a written notice to be served upon the contractor either 
personally or by leaving said notice at his residence or with his 



SPECIFICATIONS AND CONTRACTS. 


575 


agent in charge of the work. And thereupon the contractor shall 
discontinue said work or such part thereof, and the engineer shall 
thereupon have the power to place such and so many persons as he 
may deem advisable, by contract or otherwise, to complete the work, 
or such part thereof, and to use such materials as he may find upon 
the line of said work, and to procure other materials for the com¬ 
pletion of the same, and to charge the exjjense of said labor and 
materials to the aforesaid contractor; and the expense so charged 
shall be deducted and paid by the , out of such moneys as 

may be then due, or may at any time thereafter become due said 
contractor on account of work performed under these specifica¬ 
tions; and in case such expense is less than the sum which would 
have been payable if the same had been completed by the said con¬ 
tractor, he shall forfeit all claim to the difference; and in case such 
expense shall exceed said sum, he shall pay the amount of such 
excess to the 

1004. Damages for Non-completion.—The contractor shall pay 

to the , as damages for non-completion of the work within 

the time stipulated for its completion, the sum of $100 for each 
and every day which may exceed the said stipulated time for its 
completion, which said sum of $100 per day is hereby, in view of 
the difficulty of estimating such damages, agreed upon, fixed, and 
determined by the contractor and the as the liquidated 

damages that the will suffer by reason of such default, and 

not by way of penalty;* and the is hereby authorized to de¬ 

duct said sum of $100 per day from the moneys which may be due 
or become due said contractor for work under these specifications. 

1005. Evidence of the Payment of Claims.—In case of any legal 

claims being filed with the against the contractor for labor 

or materials furnished under these specifications, the said 

shall retain the whole or so much of such moneys as may be due 
or to become due the contractor as may be considered necessary to 
meet the lawful claims of such persons, until the liabilities shall be 
fully discharged and such notice withdrawn. 

1006. Protection of Persons and Property.—The contractor shall 
during the progress of the work use all proper precautions by good 
and sufficient barriers, guards, temporary bridges, etc., for the pre¬ 
vention of accidents, and at night he will put up and keep suitable 
and sufficient lights, and he will indemnify and save harmless the 




576 


HIGHWAY CONSTRUCTION. 


against and from all suits and actions, of every name and 
description, brought against it, and all costs and damages to which 
the said may be put for or on account or by reason of any 

injury or alleged injury to the person or property of another,, 
resulting from negligence or carelessness of the contractor, bis 
agents or employees, in the performance of the work, or in guarding 
the same, or from any improper materials used in its prosecution, 
or by or on account of anv act or omission of the contractor, his 
agents or employees; and the shall retain the whole or so 

much of the moneys due or to become due by reason of the work 
under these specifications as may be considered necessary, until all 
such suits or claims for damages as aforesaid shall have been settled 
and satisfactory evidence to that effect is furnished. 

1007. Bond for Faithful Performance of the Work.—The con¬ 

tractor shall execute with his sufficient sureties a bond in the sum 
of thousand dollars for the faithful performance of the 

work in accordance with the requirements of the specifications. 

1008. Power to Suspend Work.—The prosecution of the work 
may be suspended for such periods as the engineer may from time 
to time determine. No claim or demand shall be made by the con¬ 
tractor for damages'by reason of such suspensions in the work, but 
the period of such suspensions will be excluded in computing the 
time limited for the completion of the work. During such sus¬ 
pensions all materials delivered upon but not placed in the w r ork 
shall be neatly piled or removed so as to not* obstruct public travel. 
The wages of watchmen retained for the public protection during 
the period of suspension will be allowed. 

1009. Loss and Damage.—All loss and damage arising out of 
the nature of the work to be done under these specifications, or 
from any unforeseen obstructions or difficulties which may be en¬ 
countered in the prosecution of the same, or from the action of the 
elements, or from incumbrances on the line of the work, shall be 
sustained by the contractor. 

1010. Miscellaneous Work.—If any work or service be required 
to be done which in the opinion of the engineer does not come 
within the class of work to be measured under the contract, he 
shall be at liberty to direct the contractor to perform the same by 
day’s labor, and the contractor when required by him shall furnish 
such force and materials and perform such work in the manner 



SPECIFICATIONS AND CONTRACTS. 


57? 


directed, and he shall he paid the reasonable and actual wages of 
the men as ascertained by the timekeeper and the actual value of 
all materials furnished, together with fifteen per cent of the total 
amount for the use of tools and profit. The engineer shall be at 
liberty to discharge any inefficient or unsuitable workmen who may 
be placed on such work, and the work so performed will be subject 
to his approval before payment is made therefor. 

1011. Cleaning up.—All surplus materials, earth, sand, rubbish, 

and stones, are to be removed from the line of the work as rapidly 
as the work progresses. At any time within one month after the 
completion of the work, if so required by the engineer, all material 
shall be swept into heaps and removed from the line of the work ; and 
unless this be done by the contractor within forty-eight hours after 
being notified so to do to the satisfaction of the engineer, the same 
shall be removed by the , and the amount of the expense 

thereof shall be deducted out of any moneys due or to become due 
to the contractor under these specifications. 

1012. Personal Attention.—The contractor shall give his per¬ 
sonal attention to the faithful prosecution of the work, shall not 
sublet the same or any part thereof without the consent of the 

, nor will he assign by power of attorney or otherwise any 
of the moneys payable under these specifications. 

1013. Payment of Workmen.—The contractor shall punctually 
pay the workmen who shall be employed on the work comprised in 
these specifications, in cash current, and not in what is denominated 
“ store ” pay. 

1014. Prices.—The prices stated by the contractor in his tender 
and stipulated in the contract must be understood to cover every 
contingency, the furnishing of all labor, materials, power, and plant 
which may be required for the performing and completing of the 
work described in these specifications (and for maintaining the 
same in good order for a period of six months). 

1015. Payments, when Made.—The contractor shall not be 
entitled to demand or receive payment for any portion of the work 
done or materials furnished under these specifications uutil the 
same shall be fully completed in the manner set forth, and such 
completion duly certified by the engineer in charge of the work, 
and until each and every of the stipulations herein before men¬ 
tioned are complied with, and the work completed to the satisfac- 





578 


HIGHWAY CONSTRUCTION. 


tion of the and accepted by , whereupon the 

will pay in cash, on the expiration of days from the 

time of acceptance, the whole of the moneys accruing to the con¬ 
tractor under these specifications, excepting such sum or sums of 
money as may be retained under any of the provisions herein 
contained, and such sums as may have been paid in the form of 
partial payments upon the monthly estimates of the engineer. 

FORMS OF SPECIFICATIONS. 

The following forms of specifications may be of assistance in 
preparing specifications for different works. 

1016. Specifications for the Construction of a Highway from 
to in the town of , county of 

The following specifications are intended to cover the methods 
of construction and the furnishing of all the labor and materials 
necessary for the proper and workmanlike completion of the above- 
named highways in accordance with the plans on file in the office 
of the engineer, and in accordance with such instructions relating 
thereto as may from time to time be given by said engineer, or his 
assistants and inspectors. 

Description of the Work .—The character and approximate 
amounts of work to be done are as follows: 


Earth excavation. cubic yards 

Loose rock excavation. “ «* 

Solid “ “ . “ << 

Embankment to be furnished from. «« ** 

Borrovv-pits. “ «< 

Blind stone drains. lineal feet 

Tile drains, 3 inches in diameter. “ “ 

“ “ 6 “ “ “ . << «< 

Earthenware pipe-culverts, 12''diameter. “ “ 

“ “ “ 18 " “ . 

“ “ “ 24" “ . •< “ 

Dry box-culverts. cubic varc i s 

, third-class masonry. ** “ 

Dry retaining-walls. “ << 

Hip-rap. « << 

Catch- and silt-basins, number of. 

Paved gutters. lineal feet 


[Here insert the clauses suitable for each class of work in the 
schedule.'] 





















SPECIFICATIONS AND CONTRACTS. 


579 


1017. Specifications for Bulkhead (Fig. 138, p. 377). 

The bulkhead will be formed as follows: 

The piles will be of sound straight-grained spruce or other 
approved timber; they shall measure not less than 6 inches in 
diameter at the small end and not less than 12 inches nor more 
than 15 inches at the large end when cut off. The piles shall have 
the bark removed, be accurately pointed, and when required the 
heads shall be properly banded to prevent splitting or brooming 
while being driven; if found necessary, the points shall also be pro¬ 
tected with wrought-iron shoes. The piles will be spaced 6 feet 
from center to center, and shall be driven with a batter of inches 
per foot. They may be driven by the hydraulic “jet” or by an or¬ 
dinary pile-driver; if by the jet, they shall be loaded with a weight 
of 2000 pounds. By whichever method driven, they shall reach a 
total penetration into the soil and sand of not less than 15 feet 
below low-water mark. Piles injured in driving shall be drawn out 
and replaced by sound ones at the contractor’s expense. Piles 
found too short shall be drawn out and replaced by longer ones. 

Lengthening .—Lengthening by using a follower or blocking 
will not be allowed. Any pile found too short must be drawn out 
and a longer one substituted. When the piles shall have reached 
the required depth, their tops shall be sawed off evenly at the estab¬ 
lished grade. 

Pile-cap .—And thereon a pile-cap of yellow-pine timber ten 
(10) by twelve (12) inches will be laid, fastened to each pile with 
one one- (1-) inch drift-bolt eighteen (18) inches long. On the water 
face and thirty (30) inches below the top of the pile-cap there will 
be placed a 

Brace Stick of yellow pine timber five (5) by ten (10) inches, 
bolted to every second pile with one one- (1-) inch bolt eighteen 
(18) inches long. On the water face at mean high-water mark 
there will be placed' a 

Chafing-stick of yellow-pine timber five (5) by ten (10) inches, 
bolted to every pile with one one- (1-) inch bolt. On the land side 
of the piles at both mean high- and low-water marks there will be 
placed longitudinally 

Wale-sticks of yellow-pine timber five (5) by ten (10) inches, 
bolted to every pile with one one- (1-) inch bolt. 

Sheet-piling.—On the land side of the wale-sticks sheet-piling 



580 


HIGHWAY CONSTRUCTION. 


of tonguecl and grooved yellow-pine plank, three (3) inches thick 
and not less than eight (8) inches wide, will be driven to a depth 
of not less than ten (10) feet below low-water mark. Each plank 
will be spiked to both wale-sticks with two six- (6-) inch cut spikes; 
the tops will be sawed oft' level with the upper wale-stick. 

Anchor-piles .—On the land side and opposite every third pile 
and eighteen (18) feet distant therefrom an anchor-pile not less 
than six (6) inches in diameter and ten (10) feet long will be driven 
to the angle shown on plan, to a penetration of not less than seven 
(7) feet. At the back of the anchor-piles there will be placed 
loosely upon the ground a brace-stick of yellow-pine timber five (5) 
inches by ten (10) inches. 

Tension-rods .—Tension-rods made from one and one quarter 
(1^) inch iron will extend from front to rear brace-stick, passing 
through both sticks and piles; the rods will be screwed on both 
ends and will have under each nut on the water face an iron washer 
four (4) inches in diameter, cast to the required angle. 

Bolt-holes. —All bolt-holes w ill be bored with an augur one 
eigth (|) of an inch smaller than the diameter of the bolt they are 
to receive. 

Fender-piles. —Fender-piles eighteen (18) inches in diameter at 
the butt and 30 feet long will be driven at every twenty (20) feet 
along the water face. 

Lengths of Timber .—The pile-cap, braces, and chafing-sticks 
shall be in lengths of not less than eighteen (18) feet; they shall be 
arranged so as to bring the 

Joints on a pile. All joints shall be made by a twelve (12) inch 
half-lap splice fastened with two seven eighths (|-) inch by fifteen 
(15) inch bolts. All bolt-heads in pile-cap will be countersunk 
flush with the top. Iron washers will be placed under all bolt- 
heads and nuts. 

1018. Specifications for Grading, Macadamizing, Curbing, and 
Flagging Avenue, from to 

Grading .—The entire -width of the avenue is to be regulated 
and graded to sub-grade, fifteen (15) inches below finished grade, 
in accordance with the grades and cross-section shown in plans. 
Such portions as are above the grade lines shall be excavated, and 
such as are below shall be filled in. 

Slopes. —Slopes in both embankment and excavation shall be 



SPECIFICATIONS AND CONTRACTS. 


581 


one and one half (1£) horizontal to one (1) vertical unless otherwise 
ordered. 

If the material taken from the excavations is unsuitable or in¬ 
sufficient to make the embankments, the deficiency shall be sup¬ 
plied by the contractor. The material so furnished shall be good 
clean earth, sand, gravel, or broken rock and earth. If broken 
rock is furnished, the proportion of earth and rock shall not be less 
than 1 to 1, and the materials shall be so distributed that no voids 
shall be left. 

Any perishable matter that may be found at sub-grade level 
shall be removed and the space filled in with good material. 

The sub-grade surface shall be truly shaped and trimmed to 
the required cross-section, then rolled with a roller weighing not 
less than 300 pounds per inch of run. The rolling will be continued 
until the surface has become firm and hard: in no case shall it be 
less than 5 hours per 1000 square yards. Such parts as cannot be 
reached by the roller shall be tamped with hand rammers. Water 
shall be applied by sprinkling in advance of the roller, but an ex¬ 
cess must not be used; generally 25 gallons per 1000 square yards 
will be sufficient. 

On the sub-grade surface prepared as above described a layer of 
bank gravel will be spread to a depth of nine inches and rolled con¬ 
tinuously until the depth is reduced to seven inches; on the foun¬ 
dation so prepared the broken stone will be placed. Its finished 
thickness will be eight inches. The stones will be spread in two 
layers: the first layer will be spread to a depth of five and a half inches 
and rolled till the depth is reduced to five inches; water will be applied 
in advance of the roller, but not in excess. When the broken stone 
is so compacted a layer one inch thick of clean sand, or sand contain¬ 
ing not more than 15 per cent of loam, will be spread over the sur¬ 
face, and the rolling continued until the stones cease to sink or creep 
in front of the roller, and the thickness of the layer of broken stone 
is 4 inches or thereabouts. When the first layer has been finished 
to the satisfaction of the engineer, the second layer will be spread 
to the same depth and treated in the same manner as the first layer. 
The rolling of this surface will be continued until all settlement has 
ceased. 

In quality the stone must conform to the sample in the office of 
the engineer. 




582 


HIGHWAY CONSTRUCTION. 


In form it shall be as nearly cubical as practicable, and in size 
shall not exceed in any dimension two and a half inches, but may 
range f'jom this size down to quarter-inch chips; but the proportion 
of stones below one and a half inches shall not exceed 20 per cent of 
the whole quantity. The stone will not be screened, but shall he 
delivered as it comes from the breakers; care, however, being taken 
that clay does not become intermixed with the stone. 

Gutters .—For a width of two feet on each side of the carriage¬ 
way adjoining the curb a gutter of granite blocks will be laid. 
Each block shall measure not less than six nor more than nine 
inches in length, in width not less than three nor more than five 
inches in depth, not less than seven nor more than eight inches; 
the blocks to be split and dressed so as to form, when laid, close 
joints on sides and ends. 

The blocks will be laid in courses parallel to the curb. Each 
course shall be formed with blocks of a uniform width and depth,, 
and laid so that all the longitudinal joints shall be broken by a lap 
of at least two inches. 

The blocks will be laid on the gravel foundation and set stone 
to stone, both on sides and ends. When thus laid, their surface 
shall be covered with a layer of clean sharp sand, which shall be 
sw r ept with brooms until all the joints are filled. Into the sand 
joints thus made there will be poured a hot mixture of coal pitch 
and creosote. The whole surface of the blocks will then be covered 
with one half-inch of sharp sand, which shall be left undisturbed 
until ordered removed by the engineer. 

Curbing .—The curbstones shall be of bluestone, equal in quality 
to the best North River bluestone. The curbstones shall be not less 
than three feet in length, five inches thick, twenty inches deep, and 
matched width throughout. The top of the stone shall be cut to a 
bevel of one inch; the front shall be cut smooth and to a fair line, 
to a depth of fourteen inches. The ends from top to bottom shall be 
truly squared, so as to form close and even joints, and the front so 
laid as to present a fair and unbroken line. Curbstones shall be 
back filled, and backed up with at least one foot of clean, gritty 
earth, free from clay and loam. 

Circular Corners.—The curbstones at the corners of intersect¬ 
ing streets shall be cut on a curve, with true and even joints, and 



SPECIFICATIONS AND CONTRACTS. 


583 


shall be of the same description as the curb before described, and 
be laid in the same manner. 

Flagging.—All the flagging to be of bluestone equal in quality 
to the best North River bluestone, even on its face, and to measure 
not less than two feet wide, to contain not less than eight superficial 
feet, and to be in no place less than three inches thick. To be laid 
with close joints, in regular courses of four feet wide. Each stone 
shall be chisel-dressed on the four edges a distance of one inch 
down from the top and square with the face thereof, and free from 
drill-holes. 

Flagging shall be bedded in four inches of clean, gritty earth or 
steam ashes, free from clay and loam, and the work brought to an 
even surface; the joints of the flagging shall be closed up with 
cement mortar, and be left clean on the surface; the whole space of 
the sidewalks to be regulated before laying the flagging. 

Catch-basins .—Catch-basins will be constructed at the points 
indicated on the plans or wherever the engineer may direct. 

• They will be of brick masonry, built with care, of the form and 
dimensions shown on the plan. They will be made perfectly water¬ 
tight by plastering the interior with neat Portland-cement mortar one 
half-inch thick. The exterior shall be coated with cement mortar 
one inch in thickness. Each basin will be connected by a nine-inch 
cement or earthenware pipe-shoot connected to a twelve-inch cement 
or earthenware pipe. This pipe will be laid on the lines and grades 
given by the engineer, and connected to the sewer or other outlet. 

Each basin will be fitted and furnished with a cast-iron head 
and grating of the form and dimensions shown on plan. 

(Here insert such clauses for general specifications and stipula¬ 
tions as are suitable.) 

1019. Specifications for the Supply of Broken Stone. —The 

stone shall be fully equal to the sample in the engineer’s office, 
otherwise it will be rejected. 

It shall be broken in as nearly cubical form as practicable, each 
cube to have a square face and sharp edges, and shall not exceed 
in any dimension two inches, but the stones may range from this 
size down to quarter-inch chips; but the proportion of stones below 

one and a half inches shall not exceed 20 per cent of the whole 

% 

quantity. 

The broken stones shall not be screened, but will be delivered as 




584 


HIGHWAY CONSTRUCTION. 


they come from the breakers; care, however, being taken that clay 
does not become intermixed with them. 

The stone when delivered must be clean and free from clay or 
other dirt. 

The stone shall be supplied on the order of the engineer in such 
quantities as he may specify, and must be delivered within the time 
specified in the order. Failure to so deliver the stone without good 
and sufficient reason will be a valid excuse for the forfeiture of the 
contract. 

ADDITIONAL CLAUSES REQUIRED IN SPECIFICATIONS FOR 

REPAIRING, ETC. 

1020. Indemnification for Patent Claims.—The contractor shall 

indemnify and save harmless the against and from all suits 

and actions of every nature and description arising out of the claim 
or claims of any person or persons claiming to be patentees of any 
process connected with the work herein provided for, or of any 
materials used upon said work. 

1021. Indemnity Bond.—The contractor shall execute with two 

sufficient sureties a bond in the sum of thousand dollars, 

for the indemnification of the against and from all such 

suits and actions aforesaid. 

1022. Right to Construct Sewers, etc.—The right to construct 

sewers or any work in connection therewith, lay water, gas, or other 
mains and make house connections therewith, in advance of the 
pavement, is expressly reserved by the ; and the said 

may suspend the work on the pavement on any part of the line for 
the purpose above stated, without other compensation to the con¬ 
tractor for such suspension than extending the time for completing 
the work as much as it may, in the opinion of the engineer, have 
been delayed by such suspension. And the contractor shall not 
interfere with or place any impediment in the way of any person 
<ii persons who may be engaged in the construction of such works. 

1023. Old Materials.—All old materials which it may become 
necessary to remove, and where no instructions for their disposal is 
previously given, shall be considered as the property of the con¬ 
tractor, and the same shall be immediately removed by him from 
the line of the work. 




SPECIFICATIONS ANI) CONTRACTS. 


585 


1024. Security retained for Repairs.—The shall re¬ 

tain out of the moneys payable to the contractor on completion of 
the work the sum of ten cents per square yard of pavement laid 
under these specifications, which sum of ten cents with interest shall 
be paid upon the expiration of the guaranty period; provided that 
the work at that time»is in good order, or as soon thereafter as the 
work shall have been placed in good order, to the satisfaction of the 
engineer. 

During the guaranty period should any part of the work require 
repairs, the engineer shall notify the contractor to make such re¬ 
pairs, and in case of neglect or failure to make said repairs within 
forty-eight hours after service of notice the shall have the 

right to purchase such materials as may be deemed necessary, and 
to employ such persons as may be deemed proper, and to under¬ 
take and complete such repairs, and to pay the expense thereof out 
of the said sum of ten cents per square yard retained for that pur¬ 
pose, and such part of said sum as shall remain after the expenses 
of said repairs have been deducted will be paid in the manner here¬ 
inbefore described. 

1025. Alteration of Manhole Covers, Stopcock Boxes, etc.— 

All the frames and heads of sewer manholes, stopcock boxes for 
water and gas, are to be adjusted (either raised or lowered) to the 
level of the pavement. 

1026. Heads of Specifications for Repaving. 

Specifications for Regulating and Paving with Pave- 

street 

ment the Carriageway oj avenue 

(1) Description of the work. 

(2) Removal of old materials. 

(3) Excavation. 

(4) Adjustment of manhole heads, etc. 

(5) Adjustment of curb. 

(6) Adjustment of bridge stone. 

(7) Furnishing new curb. 

(8) Furnishing new bridge stones. 

(9) Preparation of roadbed. 

(10) Foundation, character of. 

(11) Concrete. 

(12) Concrete, manufacture and laying. 



586 


HIGHWAY CONSTRUCTION. 


(13) Pavement, character and quality. 

(14) Manner of laying. 

(15) Cleaning up. 

(16) Quality of material. 

(17) Inspectors. 

(18) Right to construct sewers. 

(19) Commencement of work. 

(20) Time of completion. 

(21) Suspension of work. 

(22) Extension of time. 

(23) Damages for non-completion. 

(24) Personal attention of contractor. 

(25) Contractor’s representatives. 

(26) Defective work. 

(27) Improper prosecution of the work. 

(28) Accidents or damages to persons or property to be paid for 
by the contractor. 

(29) Incompetent workmen. 

(30) Power to annul contract for violation of stipulations. 

(31) Payment of claims for labor and materials. 

(32) Measurements. 

(33) Engineer’s estimates. 

(34) Payments, when made. 

(35) Percentage retained. 

(36) Prices. 

(37) Interpretation of specifications. 

(38) Engineer defined. 

(39) Contractor defined. 

(40) Preservation of engineer marks, etc. 

(41) Indemnification of patent claims. 

(42) Indemnity bond. 

(43) Security retained for repairs. 

1027. Specifications for Street cleaning should Contain the fol¬ 
lowing Conditions.—The mode of cleaning shall be to first clean 
the gutters of all solid matter, and then sweep from the sides 
towards the centre; dirt collections not to be placed within 5 feet 
of the gutters. 

Whenever the sweeping of streets would cause the dust to rise, 
they shall be first sprinkled by sprinkling-wagons to be approved 




SPECIFICATIONS AND CONTRACTS. 


587 


by the of the of ; and the sprinkling 

shall be so done that the dust will not be turned into mud. 

All hand sweeping shall be done with push-brooms, and all sweep¬ 
ing by machinery with machines approved by the of 

All parts of streets covered with sheet asphalt shall be swept by 
machinery six times each week, between the hours of 10 p.m. and 

6 a.m., and a sufficient number of men with bass brooms shall be 
kept employed to keep them constantly clean between the hours of 

7 a.m. and 6 p.m. 

All accumulations of sweepings, and of mud or rubbish removed 
from inlets or gutters, shall be removed within three hours from 
the time such heaps are made, in carts tightly built in such a man¬ 
ner that the contents can be removed without spilling or leaking, 
and the place where they had been collected shall be swept clean. 

All gutters kept wet by the flow of filthy water or sewage shall 
be thoroughly scraped, brushed, and flushed at least twice a week 
from May 1st to November 1st, and for this work each contractor 
will be required to keep at least 100 feet of hose in each district, 
and brushes or brooms especially made for work of this kind shall 
be used in cleaning the gutters. 

All solid matter must be removed from the gutters and inlets 
before they are flushed. 

All street crossings, inlets, gutters approaching the same, and 
all gutters necessary to drain crossings within 100 feet of inlets, 
and streets in front of fire-plugs, for a radius of 5 feet, must be 
kept clean of dirt, mud, ice, and snow. 

1028. Instructions to Bidders. —Proposals for [insert descrip¬ 
tion and location of the work]. In pursuance of the follow¬ 

ing ordinance [insert ordinance]. 

Sealed proposals for the above work, indorsed with the above 
title, also with the nanies of the person or persons making the same 
and the date of presentation, will be received at the office of 

until o’clock .M., day of , 189 , at 

which place and hour the bids will be publicly opened by 
and read, and the award of the contract will be made to the lowest 
responsible bidder with adequate security as soon thereafter as 
practicable. The person or persons to whom the contract may be 
awarded will be required to attend at the office of with the 

sureties offered by him or them, and execute the contract within 





588 


HIGHWAY CONSTRUCTION". 


five days from the date of the service of a notice to the effect that 
the contract has been so awarded, and that the adequacy and suffi¬ 
ciency of the security offered has been approved by the ; 

in case of failure or neglect so to do, he or they will be con¬ 
sidered as having abandoned it, and as in default to the ; 

and thereupon the work will be readvertised and relet, and so on 
until the contract be accepted and executed. The work is to be 
commenced at such time as the engineer may designate. 

The price must be written in the bid, and also stated in figures, 
and all proposals will be considered as informal which do not con¬ 
tain bids for all the items for which prices are herein called for, or 
which contain prices for items not called for, or which contain 
erasures, alterations, or other irregularities. 

Permission will not be given for the withdrawal of any bid or 
estimate, and the right is expressly reserved by the to re¬ 

ject all bids if it shall be deemed for the public interest so to do. 
No bid will be accepted from or contract awarded to any person 
who is in arrears to the upon debt or contract, or who is a 

defaulter, as surety or otherwise, upon any obligations to the 

Bidders are required to state in their estimates, under oath, their 
names and places of residence, the names of all persons interested 
wffth them therein, and if no other person be so interested, they 
shall distinctly state the fact; also that it is made without any con¬ 
nection with any other person making a bid or estimate for the same 
work, and that it is in all respects fair and without collusion or fraud; 
and also that no member of or other officer of the 

is directly or indirectly interested therein, or in the sup¬ 
plies or work to which it relates, or in any portion of the profits 
thereof. Where more than one person is interested, it is requisite 
that the verification be made and subscribed by all the parties inter¬ 
ested. 

Each estimate shall be accompanied by the consent, in writing, 
of two householders or freeholders in the , with their re¬ 

spective places of residence, to the effect that if the contract be 
awarded to the person making the estimate, they will, upon its being 
so awarded, become bound as his sureties for its faithful perform¬ 
ance; and that if he shall omit or refuse to execute the same, they 
will pay to the any difference between the sum to which 

he would be entitled upon its completion, and that which the said 






SPECIFICATIONS AND CONTRACTS. 


589 


may be obliged to pay to tlie person to whom the con¬ 
tract shall be awarded at any subsequent letting; the amount in 
each case to be calculated upon the estimated amount of the work 
by which the bids are tested. The consent above mentioned shall 
be accompanied by the oath or affirmation, in writing, of each of 
the persons signing the same, that he is a householder or freeholder 
in the and is worth the amount of the security required 

for the completion of the contract and stated in the proposals, over 
and above all his debts of every nature and over and above his lia¬ 
bilities as bail, surety, and otherwise, and that he has offered himself 
as surety in good faith and with an intention to execute the bond 
required by law. The adequacy and sufficiency of the security 
offered will be determined by the of the 

In case a proposal is submitted by or in behalf of any corpora¬ 
tion it must be signed in the name of such corporation by some 
duly authorized officer or agent thereof, who shall also subscribe 
his own name and office. If practicable, the seal of the corporation 
should also be affixed. 

The successful bidder will be strictly held to the time bid for 
completion of the work, and to the conditions of the specifications. 

The engineer’s estimate of the nature and extent of the work to 
be done and materials to be furnished is as follows: [Insert esti¬ 
mate.] 

As the above quantities, though stated with as much accuracy 
as is possible in advance, are approximate only, bidders are required 
to submit their estimate upon the following express conditions, 
which shall apply to and become part of every estimate received: 

1. The items and quantities stated in the above schedule are 
merely approximate and may be altered in part or wholly changed 
during the progress of the work. They are intended only to indi¬ 
cate the general character of the work and shall not be made a 
basis of any claim for extra compensation of profits in case the 
quantities of the final estimate shall vary from them, nor be regarded 
as having any relation or bearing whatever upon the quantities of 
the final estimate. 

2. Bidders must satisfy themselves by personal examination of 
the site of the proposed work as to the difficulties to be encountered 
and such other matters which can in any way influence their esti¬ 
mates, and no information derived from the drawings or specifica- 




590 


HIGHWAY CONSTRUCTION'. 


tions or from the engineer or any of his assistants will relieve the 
contractor from any risks or from fulfilling the terms of the specifi¬ 
cations and contract. 

3. The contractor will be required to complete the entire work 
to the satisfaction of the and in substantial accordance 

with the specifications. 

No estimate will be received or considered unless accompanied 
by either a certified check upon one of the National or State banks 
of the drawn to the order of the , or money 

to the amount of five per centum of the amount of the security re¬ 
quired for the faithful performance of the contract. Such check or 
money must not be inclosed in the sealed envelope containing the es¬ 
timate, but must be handed to the officer or clerk of the department 
who has charge of the estimate box, and no estimate can be de¬ 
posited in said box until such check or money has been examined 
by said officer or clerk and found to be correct. All such deposits, 
except that of the successful bidder, will be returned to the persons 
making the same within three days after the contract is awarded. 
If the successful bidder shall refuse or neglect, within five days after 
notice that the contract has been awarded to him, to execute the 
same, the amount of the deposit made by him shall be forfeited to 
and retained by the as liquidated damages for such 

neglect or refusal; but if he shall execute the contract within the 
time aforesaid, the amount of his deposit will be returned to 
him. 

Bidders are particularly cautioned that in no case will they be 
permitted to use materials either in quantity or quality different 
from those described in the specifications. [And also, that a pro¬ 
vision in the specifications and contract requires the maintenance 
of the pavement in good condition for the period of from 

the final completion and acceptance thereof.] 

The amount of security is thousand dollars for the 

faithful performance of the contract, and also for the indemnifica¬ 
tion of the for infringement of patents the amount is 

thousand dollars. The contractor must notify the en¬ 
gineer in writing hours before commencing the work. 

The plans can be seen and blank forms of proposals and further 
information can be obtained on application at the office of 







SPECIFICATIONS AND CONTRACTS. 


591 


1029. Form of Proposal. 

NO. BID OR ESTIMATE. 

For [insert description of work] , made by Resid¬ 
ing at , and residing at , and resid¬ 
ing at , and residing at , composing the firm 

of 

1. declare that the only person in¬ 
terested in this proposal; and no other person other than 

herein above named ha any interest in this proposal, or in the 
contract proposed to be taken. 

2. further declare that this proposal is made without 
connection with any other person or persons making a pro¬ 
posal for the same purpose, and is in all respects fair, and without 
collusion or fraud. 

3. further declares that no member of the or 

other officer is directly or indirectly interested in this proposal, or 
in the supplies or work to which it relates, or in any portion of the 
profits thereof. 

4. further declares that the names of the persons 
affixed to the consent hereto annexed were written by said persons 
respectively, and that said persons are householders or freeholders 
in the 

5. have examined the proposals for estimates for the 

above work, dated the day of , 189 , and pub¬ 
lished in the , and the form of contract for the work 

(including the plans and specifications for the work), and have 
also visited and examined the site and location and made the in¬ 
vestigations recommended in the instructions to bidders, and 

will contract to furnish the material and perform and 
complete the work mentioned in said proposals for estimates and 
approved form of contract on the following terms, viz.: For clear¬ 
ing, grubbing and close cutting, per acre, the sum of . For 

earth excavations for all classes, per cubic yard, the sum of 
For loose rock excavation, per cubic yard, the sum of 

For solid rock excavation, per cubic yard, the sum of 

For 12-inch culvert pipe, per linear foot, the sum of 

. For 24-inch culvert pipe, per linear foot, the sum of 

For concrete, per cubic yard, the sum of . For each receiving 

basin, complete, with iron head and grating, the sum of 




592 


HIGHWAY CONSTRUCTION. 


For brick masonry, per cubic yard, the sum of 
For yellow-pine timber, including fastenings, per 1000 
feet-board measure, the sum of For spruce and other plank, 

including fastenings, per 1000 feet board measure, the sum of 
. For riprap, per cubic yard, the sum of . For dry 

stone masonry, per cubic yard, the sum of 

The above prices include the furnishing of all the materials, 
tools, plant, and labor, and every risk and contingency necessary 
for the completion of the work in accordance and with specifica¬ 
tions and plans. 

Time within which will complete the whole work ac¬ 
cording to specifications days. 


City Ge , County of , ss. : 


being duly sworn, say, each for himself, that the several matters 
stated in the above estimate are in all respects true. 

Subscribed and sworn to this day of , a.i>. 189 , 

before me, 


Comm issioner of Deeds. 

1030. Form of Agreement (to be executed in triplicate). 

This agreement made and entered into this dav of 

one thousand eight hundred and , by and between the [in¬ 
sert name of city, town, or county] of , hereinafter called the 

party of the first part, and [name of contractor], of the 
[insert place of residence], hereinafter called the party of the second 
part, 

Witnesseth: That the said party of the second part has agreed, 
and by these presents does for himself, his heirs, executors, admin¬ 
istrators, and assigns, covenant, promise, and agree with the said 
parties of the first part, for the considerations hereinafter mentioned 













SPECIFICATIONS AND CONTRACTS. 


593 


and contained, and under the penalty expressed in a bond bearing 
even date with these presents, and hereunto annexed, that he, the 
said party of the second part, his heirs, executors, administrators, or 
assigns, shall and will furnish and provide, at his own or their own 
cost and expense, all the necessary materials, appliances, tools, plant, 
and labor which are or may be necessary for the proper and sub 
stantial construction and completion of the [insert description of 
work], in accordance with the general plans on file in the office of 
the said party of the first part, and in strict conformity in every 
part and particular with the following specifications, and in accord¬ 
ance with such detail plans and instructions relating thereto as may 
from time to time be given by the chief engineer or his duly 
appointed assistants; and further agrees that the said parties of the 
first part shall be, and are hereby, authorized by their chief engineer, 
or such other person or persons, or in such other manner, as they 
may deem proper, to inspect the material to be furnished and the 
work to be done under this agreement, and to see that the same 
correspond with the specifications and conditions hereinafter set 
forth. 

The party of the second part admits and agrees that the amounts 
and quantities of materials to be furnished and work to be done, as 
stated in the proposals for estimates for the said work, are approxi¬ 
mate only ; that he is satisfied with the foregoing estimate in de¬ 
termining the price according to which he agrees to do the work 
required by this contract in accordance therewith, and that he shall 
not and will not dispute or complain of such statement, nor assert 
that there was any misunderstanding in regard to the nature or 
amount of the materials to be furnished or work to be done; and 
he covenants and agrees that he will complete the entire work to 
the satisfaction of the and in substantial accordance with 

said specifications and the plan therein mentioned, and that he will 
not ask, demand, sue for, or recover for the entire work any extra 
compensation beyond the amount payable for the several classes of 
work in this contract enumerated, which shall be actually performed, 
at the price therefor herein agreed upon and fixed. 

The parties hereto also declare that this contract is made with 
reference to the proposals for estimates for the above-described 
work, hereto annexed, and the estimate of the contractor now on file 







594 


HIGHWAY CONSTRUCTION. 


in the , which are to be taken as part and parcel of these- 

presents [here insert specifications and general stipulations]. 

Commencement .—The said party of the second part hereby 
further agrees to commence the work comprised under this agree¬ 
ment on such day and at such place or places as the engineer may 
designate. Failure to so commence will be authority for the party 
of the first part to declare this agreement forfeited, and the said 
party of the first part may proceed with the execution of the work 
in such manner as they may deem proper. 

Time of Completion .—The party of the second part agrees to 
prosecute the work in such manner as to complete the same in 
accordance with this agreement on or before the expiration of two 
hundred (200) days after the date of commencement, and it is- 
further agreed that in the computation of said time, the length of 
time (expressed in days and parts of a day) during which the work 
or any part thereof has been delayed in consequence of the condi¬ 
tion of the weather, or by any difficult circumstances so unusual 
that they could not be foreseen previous to, or avoided during, the 
construction of the work, or by any act or omission of the parties 
of the first part (all of which shall be determined by the chief en¬ 
gineer, who shall certify to the same in writing), and also Sundays 
and holidays on which no work is done, and days on which the 
prosecution of the work is suspended by order of the party of the 
first part, shall be excluded. 

But if the construction of said work should require material or 
work in greater or lesser quantities or amounts than those men¬ 
tioned and set forth in the engineer's estimate, then the said time 
shall be increased or diminished as much as the said engineer, by 
a certificate in writing, shall deem just and reasonable, and fairly 
proportioned to the amount of said increase or diminution. 

But neither an extension of time for any reason beyond the date 
fixed herein for the completion of the work, nor the doing and ac¬ 
ceptance of any part of the work called for by this agreement, 
subsequent to the said date, shall be deemed to be a waiver by the 
said party of the first part of the right to abrogate this contract for 
abandonment or delay in the manner provided for in Article 80 of 
this agreement. 

Damages for Non-completion— And the said party of the second 
part hereby further agrees, that the said parties of the first part 



SPECIFICATIONS AND CONTRACTS. 


595 


shall be and are hereby authorized to deduct and retain out of the 
moneys which may be due or become due to the said party of the 
second part under this agreement, as damages for the non-comple¬ 
tion of the work aforesaid within the time hereinbefore stipulated 
for its completion, the sum of dollars for each and every day 

which may exceed the said stipulated time for its completion; which 
said sum of dollars per day is hereby, in view of the difficulty 

of estimating such damages agreed upon, fixed and determined by 
the parties hereto as the liquidated damages that the parties of the 
first part will suffer by reason of such default, and not by way of 
penalty. 

Improper Prosecution of WorJc .—The said party of the second 
part further agrees that if at any time it should appear to the en¬ 
gineer that the works are being delayed, or are not being prosecuted 
with due diligence, or with such speed as would be necessary for 
their completion within the time specified, or that the works are 
being prosecuted in an improper or unworkmanlike manner, the said 
engineer shall notify the contractor in writing, sjoecifying the causes 
of complaint, and upon the party of the second part failing to 
rectify such matters within seven days after the receipt of said 
notice, the engineer shall notify the party of the first part of such 
failure; and it is further agreed, that in the event of such failure 
the party of the first part may, without further notice, suspend the 
contractor from all work under this agreement; and it is further 
agreed, that the said party of the second part shall immediately 
respect said suspension, and shall stop work, and cease to have any 
rights to possession of the ground; and the said party of the first 
part shall thereupon have the power to carry on and complete the 
work herein described, by contract or otherwise, employing such 
plant, tools, and materials as may be on the ground, and procuring 
such others as may be wanting, for the proper completion of the 
work, and to charge the expense of such labor and materials to the 
aforesaid party of the second part, and the expense so charged 
shall be deducted and paid out of such moneys as may be then due,, 
or may at any time thereafter become due, to the said party of the 
second part under or by virtue of this agreement, or any part 
thereof; any excess of cost over and above the amount accruing as 
above stated shall be charged against the party of the second part 
ana his sureties, who will each and severally be held liable there- 




596 


HIGHWAY CONSTRUCTION. 


for; and in case the cost of completion shall he less than the sum 
which would have been payable under this contract if the same had 
been completed by the party of the second part, he shall be entitled 
to receive the difference. 

Engineer’s Returns .—The said party cf the second part further 
agrees that the return of the engineer shall be the account by 
which the amount of material furnished and work done in terms 
of this contract shall be computed; provided, however, that nothing 
herein contained be construed to affect the right of the party of the 
first part to reject and contest any return or certificate of the en¬ 
gineer or inspectors having charge of the work, should such return 
or certificate be in their opinion not in accordance with the facts 
of the case or the requirements of this agreement, or otherwise 
improperly given. 

Damage to Property .—And it is hereby further agreed, that 
in case any damage or injury shall or may result to buildings, 
water-pipes, hydrants, gate-boxes, sewer-basins, man-holes, sewers, 
or other works through or by reason of any negligence, careless¬ 
ness, or want of skill on part of said party of the second part, the 
said party of the second part shall restore the same to their former 
good condition; failing to do so, said party of the second part 
shall pay such amount as shall or may be sufficient to cover the 
expense and damage occasioned by such negligence, carelessness, 
or unskilfulness. 

Gas-pipes .—And the said party of the second part further 
agrees to do everything necessary to support and sustain the gas- 
pipes laid in or across said streets, which may be liable to any in¬ 
jury from digging the trenches for the work hereinbefore men¬ 
tioned, and to have a sufficient quantity of timber and plank con¬ 
stantly on the ground, and to use the same as required for bracing 
and sheet-piling the sides of the excavation. 

Notice to Gas Companies .—And the said party of the second 
part further agrees to give notice in writing, at least twenty-four 
hours before breaking ground for the purpose of constructing the 
work hereinbefore mentioned, to such and all such gas companies 
as have, or may during the progress of the work have, any gas-pipes 
which may be affected by such excavations as may become 
necessary. 

And it is further agreed, that the said party of the second part 







SPECIFICATIONS AND CONTRACTS. 


597 


shall not cause any hindrance to or interfere with such gas com¬ 
pany or companies in protecting their pipes, nor in removing or 
otherwise protecting and replacing the main and service pipes, 
lamp-posts and lamps, where necessary; but that the said jiarty of 
the second part will suffer the said company or companies to take 
all such measures as may become necessary for the purpose afore¬ 
said. 

Penalty of Damage to Gas-pipes .—And it is hereby further 
agreed, that in case any damage or injury shall or may result to the 
said pipes, lamp-posts, lamps, or other works of any gas company, 
through or by reason of any negligence, carelessness, or want of 
skill on the part of the said party of the second part, his agents or 
servants, the said party of the second part shall become liable to 
pay such amount as shall or may be sufficient to cover the expense 
and damage occasioned by such negligence, carelessness, or unskil¬ 
fulness; and such amount shall be charged against the said party 
of the second part, and may be deducted from any sum or sums 
due or to become due or payable to said party of the second part on 
account of this contract. 

Water-pipes .—The party of the second part hereby further 
agrees to sustain in their places, without injury, all the main and 
service water-pipes which may be affected in any manner by the 
work under this agreement, including any such protective meas¬ 
ures as may be required in cold weather to prevent them from 
freezing; or failing to do so, the said shall be and he is 

hereby authorized to replace and recalk and repair the same im¬ 
mediately in each block, as the work progresses, and the cost there¬ 
of shall be charged to the said party of the second part, and the 
cost so charged to the said party of the second part shall be re¬ 
tained and deducted, and the parties of the first part are hereby 
authorized to retain and deduct said cost out of the moneys which 
may be due or become due to the said party of the second part 
under this agreement. 

Transfer of Contract .—The party of the second part further 
agrees not to transfer or sublet any part of the work referred to in 
this agreement, without the previous written consent of the en¬ 
gineer; any such transfer or subletting without said consent will 
be null and void, and will be sufficient cause for the annulment of 





598 


HIGHWAY CONSTRUCTION. 


the contract; nor shall any of the moneys payable under this con¬ 
tract be assigned by power of attorney or otherwise. 

Loss or Damage .—And it is further agreed that all loss.or 
damage arising out of the nature of the work to be done, or from 
any unforeseen or unusual obstructions or difficulties which may 
be encountered in the prosecution of the same, or from the action 
of the elements, or from injury to persons or property of another, 
resulting from negligence in the performance and guarding of the 
same, which must be protected when necessary with barriers, and 
at night with red lights, or from any improper materials used in 
prosecution or by or on account of any act or omission of his own, 
or his agents, will be sustained by the contractor, and he shall save 
harmless the party of the first part from any and all liabilities and 
claims for such, and the said party of the first part shall have the 
right to retain any moneys that may be due or become due, until 
evidence has been furnished that all such suits or claims for 
damages as aforesaid have been satisfactorily settled. 

Public T J rotection .—It is further agreed that the contractor 
will enclose every opening he may make in the public highway 
with sufficient barriers, and must maintain red lights at the same 
at night, and must take all necessary precautions to guard effectu¬ 
ally against accidents to persons, horses, vehicles, or property of 
any kind, and all work shall be done in such manner and at such 
times as to interfere as little as possible with public travel and 
convenience; and the contractor shall conduct his work for this 
object as the engineer may from time to time direct. 

Work not Provided for in Contract .—The said party of the 
second part further agrees, that if, before the completion of the 
work contemplated herein, it shall become necessary to do any 
other or further work on or about this regulating, etc., than is pro¬ 
vided for in this contract, or to construct anv sewer or sewers or 
appurtenances thereof, on the line of this work, the said party of 
the second part will not in any way interfere with or molest such 
other person or persons as the may employ to do such work, 

and will suspend each part of the work herein specified, or will 
carry on the same in such manner as mav be ordered bv the said 
, to afford all reasonable facilities for doing such work, 
and no other damage or claim by the said party of the second part 
hereof shall be allowed except such extension of the time specified 



SPECIFICATION'S AND CONTRACTS. 


599 


in this contract for the performance thereof as the may 

deem reasonable. 

Security to be retained for Repairs .—And the said party of 
the second part hereby further agrees that the said parties of the 
first part shall be and are hereby authorized to retain, out of the 
moneys payable to him under this agreement, the certain sum of 
twenty-five cents per linear, foot of the work done under this agree¬ 
ment, and to expend the same, in the manner provided for, in mak¬ 
ing such repairs to the work done under this agreement as the said 
may deem necessary, except curbing and flagging, which 
will be finally accepted upon the completion of the work. And it 
is further agreed that if, at any time during the period of six 
months from the date of the acceptance by said of the 

work under this agreement, the said work or any part thereof (ex¬ 
cepting only such part or parts of the work as after the completion 
thereof may have been disturbed in the construction or repairs of 
sewers or drains, or in laying or repairing gas or water main or 
service pipes, or railroad-pier foundations) shall in the opinion of 
the . said require repairs, the said shall notify the 

said party of the second part to make the repairs so required, the 
said party of the second part shall immediately commence and 
complete the same to the satisfaction of said ; and in 

case of failure or neglect, on his part, to do so within forty-eight 
hours from the date of the service of the aforesaid notice, then the 
said shall have the right to purchase such materials as he 

shall deem necessary, and to employ such person or persons as he 
may deem proper, and to undertake and complete the said repairs, 
and to pay the expense thereof out of the said certain sum retained 
for that purpose by the said parties of the first part, as before men¬ 
tioned. And the parties of the first part hereby agree, upon the 
expiration of the said period of six months, provided that the said 
work at that time be in good order, or as soon thereafter as the said 
work shall have been put in good order to the satisfaction of the 
said , to pay to the said party of the second part the whole 

of the sum last aforesaid or such part thereof as may remain after 
the expense of making such repairs, in the manner aforesaid, shall 
have been paid therefrom. And it is hereby further agreed, between 
the parties hereto, that if the termination of the said period of six 
months after the completion and acceptance of the work done 



600 


HIGHWAY CONSTRUCTION. 


under this agreement shall fall within the months of December, 
January, February, and March, then in that case the said months 
of December, January, February, and March, or such part thereof 
as the may determine, shall not be included in the compu¬ 

tation of the said period of six months. 

Prices .—And the party of the second part hereby further agrees 
to receive the prices set forth in the following schedule as full 
compensation for furnishing all materials and labor, and the doing 
of all work, including all loss or damage arising out of the nature of 
the work, or from the action of the elements, or from any unforeseen 
obstructions or difficulties, which may be encountered in the jrrose- 
cution of the same; also all expenses incurred by or in consequence 
of the suspension or discontinuance of said work which may be 
required in building and constructing, and in all respects complet¬ 
ing the aforesaid [insert description of work], including all appur¬ 
tenances and accessories, to the satisfaction of the engineer and the 
hereinbefore mentioned authorities, and in the manner and under 
the conditions hereinbefore specified, to wit: [insert schedule of 
prices]. 

Manner of Payment .—And the said party of the second part 
further agrees that he shall not be entitled to demand or receive 
payment for any of the aforesaid work or material until the same 
shall be fully completed in the manner set forth in this agreement, 
and such completion duly certified by the chief engineer, and until 
each and every one of the stipulations hereinbefore mentioned are 
complied with. 

Whereupon the parties of the first part will pay, and hereby 
bind themselves and their successors to pay, to the said party of the 
second part, on account, ninety (90) per cent of the monthly esti¬ 
mate of the whole amount of money accruing to the said party of 
the second part, and the reserved ten (10) per cent upon the formal 
acceptance of the work by the party of the first part. 

In witness whereof, the ha hereunto set 

hand and seal on behalf of the said parties of the first part, and 
the said party of the second part hath also hereunto set 
hand and seal , the day and year first above written; and said 
commissioner and party hereto of the second part hath executed 
this agreement in triplicate, one part of which is to remain with 



SPECIFICATIONS AND CONTRACTS. 


601 


the said , one other to be filed with the , and the 

third to be delivered to the said party hereto of the second part. 

Signed and sealed in presence of 


Contractor . 

\ 

State of , City of , County of , ss. : 

On this day of , 189 , before me personally came 

to me known, and known to me to be the , the person de¬ 

scribed in and who executed the foregoing instrument, and he 
acknowledged to me that he executed the same as such , 

for the purposes therein mentioned. 

Commissioner of Deeds, 
. ... County, 

State of , City of , County of , ss.: 

On this day of 189 , before me personally came 

to me known, and known to me to be the person described in and 
who executed the foregoing instrument, and he acknowledged 
to me that he executed the same for the purposes therein men¬ 
tioned. 


Commissioner of Deeds, 
.County. 

1031. Form of Bond. 

Know all men by these presents, that we, 

of the , are held and firmly bound unto the of the 

in the sum of thousand dollars lawful money of 

the United States of America, to be paid to the said , or 

to their certain attorney, successors, or assigns; for which pay¬ 
ment, well and truly to be made, we bind ourselves, and our several 
and respective heirs, executors, and administrators, jointly and 
severally, firmly by these presents. 










002 


HIGHWAY CONSTRUCTION - . 


Sealed with our seals. Dated this day of , one 

thousand eight hundred and 
Whereas , the above bounden 

by an instrument in writing under hand and seal , 

bearing even date with these presents, ha contracted with the 
said to furnish all the materials and labor, and in a good, 

firm, and substantial manner construct [description of work]: 

Now, therefore, the condition of the above obligation is such, that 
if the said above bounden 

or executors, administrators, or assigns, shall well and 

truly, in a good, sufficient, and workmanlike manner, perform the 
work mentioned in the aforesaid agreement, in accordance with the 
terms and provisions therein stipulated, and in each and every re¬ 
spect comply with the conditions and covenants therein contained, 
then this obligation to be void; otherwise to remain in full force 
and virtue. 


Signed and sealed in presence of 


State of , City of , County of , ss.: 

On this day of , 189 , before me personally came 

to me personally known, and known to me to be the same persons 
described in and who executed the foregoing obligation, and sev¬ 
erally acknowledged that they executed the same. 

Commissioner of Deeds , 

.County. 


State of , City of , County of , ss . : 

I , of said , being duly sworn, do depose and say, 

that I am a holder in the of and in 











SPECIFICATIONS AND CONTRACTS. 


603 


said , and that I am worth the sum of one thousand dollars 

over and above all my debts and liabilities, including my liabilities 
as bail, surety, and otherwise, and over and above all my property 
which is exempt by law from execution. 

Subscribed and sworn to this 
day of , 189 , before me, 



Commissioner of Deeds, 
.County. 






CHAPTER XXIII. 



Fig. 187.— Axe Mattock. 


Axes. 

Bush-hooks, bandied 

Grub-hoes... 

Mattocks.. 

Stump-pulling machines 
Cross-cut saws. 



Fig. 188. —Pick Mattock. 


price per dozen $12.00 to $15.50 

“ “ “ 17.00 

“ “ “ 11.00 to 17.00 

“ “ “ 15.50 “ 18.00 

.each 150.00 “ 250.00 

.per foot 0.68 

604 



TOOLS AND MACHINERY EMPLOYED IN THE CONSTRUCTION 

OF HIGHWAYS. 

The implements employed in the construction of highways and 
pavements are many and varied. A brief description of the prin¬ 
cipal ones, and the range in price, is given in the following pages. 
The prices stated are only approximate and will vary, depending 
upon the quantity required and the condition of the market. 

1032. Tools for Clearing and Grubbing. 


Fig. 186.—Bush-hooks. 














TOOLS AND MACHINERY EMPLOYED. 


605 


1033. Tools for Grading. —Picks are made of various styles, ac¬ 
cording to the class of material in which they are to be used. 
Fig. 189 shows the form usually employed in street work. Fig. 190 
shows the form generally used for clay or gravel excavation. 

The eye of the pick is generally formed of wrought iron, pointed 
with steel. 

The weight of picks ranges from 4 to 9 lbs., and cost per dozen 
$8.50 to $35. 



Fig. 189.—Grading-pick. 



Fig. 190.—Clay-pick. 

Shovels are made m two forms, square- and round-pointed, 
usually of pressed steel. They cost from $7 to 813 per dozen for 
the square-pointed and from $7.25 to $13.50 for the round-pointed. 



Fig. 191.— Shovels. 


Ploughs are extensively employed in grading, special forms 
being manufactured for the purpose. They are known as “ grading- 
ploughs/’ “road-ploughs,” “breaking-ploughs,” “township-ploughs,” 
etc. They vary in form according to the kind of work they are 
intended for, viz., loosening earth, gravel, hardpan, and some of 
the softer rocks. 

These ploughs are made of great strength, selected white oak, 
rock elm, wrought steel and iron being generally used in their con¬ 
struction. 

The cost of operating ploughs ranges from 2 to 5 cents per 
cubic yard, depending upon the compactness of the soil. 










606 


HIGHWAY CONSTRUCTION. 



Fig. 193. —Hardpan-plougu. 


The quantity of material loosened will vary from 2 to 5 cubic 
yards per hour. 

Fig. 192 shows the form usually adopted for loosening earth. 
This plough does not turn the soil, but cuts a furrow about 10 inches 


Fig. 192.—Grading-plougii. 

wide and of such a depth as it may be regulated for up to ll inches. 

In light soils the ploughs are operated by two or four horses; in 
heavy soils as many as eight are employed. 

Grading-ploughs vary in weight from 100 to 325 lbs., in price 
from $22 to $65. 

Fig. 193 illustrates a plough specially designed for tearing up 
macadam, gravel, or similar material. The point is a straight bar 
of cast steel drawn down to a point, and can be easily repaired. 
Price about $40. 
























































































TOOLS AND MACHINERY EMPLOYED. 


607 


Scrapers are generally used to move the material loosened by 
ploughing; they are made of either iron or steel, and in a variety of 
forms, and are known by various names, as “drag,” “buck,” 
“pole,” and “wheeled.” 

The drag-scrapers are usually employed on short hauls, the 
wheeled on long hauls. 

Tigs. 194 and 195 illustrate the usual form of drag-scrapers. 



Fig. 194.—Diiag-scraper. 


Drag-scrapers are made in three sizes. The smallest, for one 
horse, has a capacity of 3 cubic feet; the others, for two horses, 
have a capacity of 5 to cubic feet. The smallest weighs about 
90 lbs., and the larger ones from 94 to 102 lbs. 



Fig. 195.— Drag- scraper with Runners. 






















0 


608 


HIGHWAY CONSTRUCTION. 


The price is variable, iron being the cheapest and steel the 
dearest; the range appears to be from $10 to $18. 

A recent improvement in drag-scrapers is the furnishing them 
with runners or a double bottom. These devices prolong the life 
of the scraper. Fig. 195 shows a drag-scraper furnished with steel 
runners. 

Buck-scrapers are made in two sizes—two-liorse, carrying 7-J 
cubic feet; four-horse, 12 cubic feet. 

Pole-scraper Fig. 196 is designed for use in making and levell¬ 
ing earth roads and for cutting and cleaning ditches; it is also 
well adapted for moving earth short distances at a minimum 
cost. 



Fig. 196—Pole-scraper. 


SIZE AND PRICE. 

48 in. wide, weight 123 lbs. 

36 “ “ “ 113 “. 


$14 

13 


Wheeled scrapers consist of a metal box, usually steel, mounted 
on wheels, and furnished with levers for raising, lowering, and 
dumping. They are operated in the same manner as drag scrapers, 
except that all the movements are made by means of the levers, 
and without stopping the team. By their use the excessive resist¬ 
ance to traction of the drag-scraper is avoided. Various sizes are 
made, ranging in capacity from 10 to 17 cubic feet. In weight they 
range from 350 to 700 lbs.; in price from $40 to $75. 

Figs. 197 to 199 show the three positions of the scrapers when 
in use. 




















TOOLS AND MACHINERY EMPLOYED 


609 






Fig. 197.— Position when Loading. 




Fig. 199. —Position when Unloaded. 


» 




























































610 


HIGHWAY CONSTRUCTION. 


Wheelbarrows.— The wheelbarrow Fig. 200 is constructed of 
wood and is the one most commonly employed for earthwork. Its 
capacity ranges from 2 to 2-j-. cubic feet. Weight about 50 lbs. 
Price about $20 per dozen. 

The barrow Fig. 201 has a pressed-steel tray, oak frame, and steel 
wheel, and will be found more durable in the maintenance depart¬ 
ment than the all-wood barrow. Capacity from 3^ to 5 cubic feet, 
depending on size of tray. Price from $5.50 to $7.50. 

The barrow Fig. 202 is constructed with tubular iron frames and 
steel tray, and is adaptable to the heaviest work, such as moving 
heavy broken stone, etc., or it may be employed with advantage in 
the cleaning department. Capacity from 3 to 4 cubic feet. Weight 
from 70 to 82 lbs. Price from $10.75 to $13.50. 



Fig, 200. 



Fig. 201. 



Fig. 202. 


The maximum distance to which earth can be wheeled economi¬ 
cally in barrows is about 200 feet. 

The wheeling should be performed upon planks, whose steepest 
inclination should not exceed 1 in 12. The power required to move 
a barrow on a plank is about ^ part of the weight; on hard dry 
earth, about part of the weight. 

The time occupied in loading a barrow will varv with the char¬ 
acter of the material and the proportion of wheelers to shovellers. 
Approximately, a shoveller takes about as long to fill a barrow with 
earth as a wheeler takes to wheel a full barrow a distance of about 





TOOLS AND MACHINERY EMPLOYED. 


611 


100 or 120 feet on a horizontal plank and return with the empty 
harrow. 

Carts. —The cart usually employed for hauling earth, etc., is 
shown in Fig. 203. The average capacity is 22 cubic feet, and the 
average weight is 800 lbs. Price about $75. 

These carts are usually furnished with broad tires, and the body 
is so balanced that the load is evenly divided above the axle. 

The time required to load a cart varies with the material. One 
shoveller will require about as follows : clay, seven minutes ; loam, 
six minutes ; sand, five minutes. 



Fig. 203.— Earth-cart. 


Dump-cars. —These cars are made to dump in several different 
ways, viz., single or double side, single or double end, and rotary 
or universal dumpers. 

Dump-cars may be operated singly or in trains, as the magni¬ 
tude of the work may demand. They may be moved by horses or 
small locomotives. They are made in various sizes, depending upon 
the gauge of the track on which they are run. A common gauge is 
20 inches, but varies from that up to the standard railroad gauge 
of 56^- inches. 

The principal dimensions, capacity, prices, etc., of siugle-side 
dumping-cars are given in the following table. Those made by 
different manufacturers vary, but not materially, from these stated. 















C12 


HIGHWAY CONSTRUCTION 



Fig. 204 —Side Dumping-car. 














TOOLS ANI) MACHINERY EMPLOYED 


613 



— 






^;vv 

. 


——. 


Fig. 205. —Rotary Dumping-car. 


DIMENSIONS, CAPACITY, 


PRICES, ETC., 


OF DUMP-CARS. 


Gauge. 

Inches. 

Dimensions. 

Capacity. 

Cubic Yards. 

Price. 

i-4 

<v 

> 

o 

S3 

■i-t * 

c -ri 

J 

Wheel¬ 
base. : 

Length of 
Body. 

Width. 

Depth. 

Top of Body 
above Rail. 

Diameter of 
Wheels. 

Diameter of 
Axles. 

Weight. 


ft. in. 

ft. in. 

ft. in. 

ft. in. 

- in. 

ft. in. 

in. 

in. 

lbs. 



20 

7 5 

3 3 

5 0 

5 0 

16 

4 0 

16 

2£ 

1300 

n 

$64 

30 

It 

. k 

U 

t 4 

t« 

a 

k k 

kt 

1400 

i • 

67 

36 

» ( 

U 

U 

u 

it 

t ( 

tc 

u 

1450 

u 

70 

36 to 561 

8 4 

3 5 

6 0 

6 0 

24 to 30 

(4 

20 

u 

2000 

to 3 

100 to 110 


Track and Track Fastenings. —The rails used on con¬ 
struction range from 12 to 25 lbs. per yard. The price varies con¬ 
siderably with the condition of the market. 








































G14 


HIGHWAY CONSTRUCTION. 


The number of tons of rails required £>er mile is as follows: 


Weight per yard. 

12 lbs... .. 

4 

Tons of 2240 lbs. 
per mile. 

Ifi “. 


.. 25 “ 

320 “ 

20 “ . 


..31 “ 

960 “ 

25 “ . 


.. 39 “ 

640 “ 

28 “. 


.44 “ 

000 “ 


The number of cross-ties per mile is as follows: 


Centre to Centre. No. of Ties 

1 h feet. 3.520 

If “. 3.017 

2 “.2.640 

2f “. 2.348 

2£ “. 2.113 


The number of splice-joints per mile is as follows (two bars 
and four bolts and nuts to each joint): 


Rails 20 feet long 
<< 24 iC 4 ( 

“ 26 “ 

“ 28 “ 

“ 30 “ “ , 


528 joints 
440 “ 

406 “ 

378 “ 

352 “ 


The size of spikes used and the number required per mile is as 
follows (four spikes per tie): 


Weight of Rail. 

Size, measured 
under head. 

Ties, 2 ft. 

C. to C., 
require Kegs 

Average Number 
per Keg of 200 lbs. 

24 to 35 lbs. 

4" X V 

17f 

600 

20 to 30 “ 

4 X tV 

14f 

720 

16 to 25 “ 

4X1 

m 

1000 

16 to 20 " 

3£ X f 

9 

1190 

16 to 20 “ 

3X| 

81- 

1240 

12 to 16 “ 

2i X 1 

n 

1342 


Dump- wagons, Figs. 206 and 207. —The use of these wagons 
for moving excavated earth, etc., and for transporting materials 
such as sand, gravel, etc., materially shortens the time required for 































TOOLS AND MACHINERY EMPLOYED 


615 


unloading the ordinary form of contractor's wagon;having no reach 
or pole connecting the rear axle with the centre hearing of the front 
axle, they may be cramped short and the load deposited just 



Fig. 206. —Dump-wagon 



Dump-wagon Dumped 
























































610 


HIGHWAY CONSTRUCTION. 




where required. They are operated by the driver, and the capacity 
ranges from 35 to 45 cubic feet. 

Mechanical Graders. —Within the last few years several 
machines have been devised for the purpose of handlingearth more 

f 


Fig. 208.— Road-grader. 

expeditiously and economically than can be done by hand; they 
are called by various names, such as “ road machines,” “ graders,” 
“ road-hones,” etc. Their general form is shown in Figs. 208 to 
210 . 


Fig. 209. —Road-grader. 

Briefly described, they consist of a large blade made entirely of 
steel or of iron, or wood shod with steel, which is so arranged by 
mechanism attached to the frame from which it is suspended that 











TOOLS AND MACHINERY EMPLOYED. 


617 


it can be adjusted and fixed in any direction by the operator. In 
their action they combine the work of excavating and transporting 
the earth. They have been chiefly employed in the forming and 
maintenance of earth roads, but may be also advantageously used 
in preparing the subgrade surface of roads for the reception of 
broken stone or other improved covering. 

A large variety of such machines are on the market, and the 
price ranges from $100 to $300. 



Fig. 210. —Road-grader. 


Besides the above-described machines, there is another known as 
the “ New Era” grader, shown in Fig. 211. This machine ex¬ 
cavates the material from side ditches, and automatically places it 
in the embankment, or it can be used in a cutting, in which situ¬ 
ation it will excavate and automatically load the material into carts 
or wagons. Fig. 212 shows the machine at work. 

Briefly described, the machine consists of a plough which 
loosens and raises the earth, depositing it upon a transverse carry¬ 
ing-belt, which conveys it from excavation to embankment. This 
carrier is built in four sections, bolting together, so it can be used 
to deliver earth at 14, 17, 19, or 22 feet from the plough. The 
carrier-belt is of heavy 3-ply rubber 3 feet wide. 

The plough and carrier are supported by a strong trussed frame¬ 
work resting on heavy steel axles and broad wheels. The large 
rear wheels are ratcheted upon the axle, and connected with strong 



















618 


HIGHWAY CONSTRUCTION 


gearing which propels the carrying-belt at right angles to the 
direction in which the machine is moving. 



Fig. 211.—New Era Grader. 



Fig. 212.—New Era Grader at Work. 


The wheels and trusses are low and broad, occupying a space 8 
feet wide and 14 feet long, exclusive of the side carrier. This en¬ 
ables it to work on hillsides where any wheeled implement can be 













































TOOLS AND MACHINERY EMPLOYED. 


619 


used. Notwithstanding its large size it is so flexible that it may be 
turned around on a 16-foot embankment. Pilot-wheels and levers 
enable the operator to raise or lower the plough or carrier at 
pleasure. 

As a motive power 12 horses—8 driven in front, 4 abreast, and 
4 in the rear on a push-cart—are usually employed. 

When the teams are started, the operator lowers the plough and 
throws the belting into gear, and as the plough raises and turns the 
earth to the side the belt receives and delivers it at the distance 
for which the carrier is adjusted, forming either excavation or 
embankment. 

When it becomes necessary to deliver the excavated earth be¬ 
yond the capacity of the machine (22 feet or feet above the 
plough), the earth is loaded upon wagons, then conveyed to any 
distance. Arranging the carrier at. 19 feet, wagons are driven 
under the carrier and loaded with 1^ to 1^ yards of earth in from 
20 to 30 seconds. When one wagon turns out with its load, an¬ 
other drives under the carrier, and the machine thus loads 600 to 
800 wagons per day. 

The makers claim that with six teams and three men it is capa¬ 
ble of excavating and placing in embankment from 1000 to 1500 
cubic yards of earth in ten hours, or of loading from 600 to 800 
wagons in the same time, and that the cost of this handling is 
from li to 2i cents per cubic yard. 

Points to be Considered in Selecting a Road Machine. 
—In the selection of a road machine the following points should be 
carefully considered: 

(1) Thoroughness and simplicity of its mechanical construction. 

(2) Material and workmanship used in its construction. 

(3) Ease of operation. 

(4) Lightness of draft. 

(5) Adaptability for doing general road-work, ditching, etc. 

(6) Safety to the operator. 

Care of Road Machines. —The road machine when not in 
use should be stored in a dry house and thoroughly cleaned, its 
blade brushed free from all accumulations of mud, wiped thor¬ 
oughly dry, and well covered with grease or crude oil. The axles, 
journals, and wearing parts should be kept well oiled when in use. 



620 


HIGHWAY CONSTRUCTION. 


and the blade should be kept sharp and in good condition at all 
times. An extra blade should be kept on hand to avoid stopping 
the machine while the dulled one is being sharpened. 

Surface-graders. —The surface-grader, Fig. 213, is used for 
removing earth previously loosened by a plough. It is operated by 
one horse. The load may be retained and carried a considerable 



Fig. 213.—Surface-grader. 

distance, or it may be spread gradually, as the operator desires. It 
is also employed to level off and trim the surface after scrapers. 

J he blade is of steel, \ inch thick, 15 inches wide, and 30 inches 
long. The beam and other parts are of oak and iron. Weight 
about 60 lbs. Price about $9. 



Fig. 214.—Road-leveller. 


Ihe road-leveller, big. 214, is used for trimming and smoothing 
the surface of earth roads. It is largely employed in the spring 
when the frost leaves the ground. 

The blade is of steel, J inch thick by 4 inches by 72 inches, and 
is provided with a seat for the driver. It is operated by a team of 
horses. Weight about 150 lbs. Price about $12. 























TOOLS AND MACHINERY EMPLOYED. 


621 


1034. Draining-tools.—The tools employed for digging the 
ditches and shaping the bottom to fit the drain-tiles are shown in 
Fig. 215. They are convenient to use, and expedite the work by 
avoiding unnecessary excavation. For cost of drains, etc., see Art. 
688, et seq. 


I 



No. i. 



No. 3. 



No. i 


Fig. 215.—Draining-tools. 


The tools are used as follows : Nos. 3, 4, and 5 are used for 
digging the ditch; Nos. 6 and 7 for cleaning and rounding the 
bottom of the ditch for round tile. No. 2 is used for shovelling 
out loose earth and levelling the bottom of the ditch; No. 1 is 
used for the same purpose when the ditch is intended for “sole'” 

tile. 
































HIGHWAY CONSTRUCTION - . 


C 


jo 

/V /V 


1035. Tools for Rock Excavation —Hand Drilling. —The tools 
employed for hand drilling are illustrated in Fig. 216, in which Fig. 
A represents the first or shortest drill, usually eighteen inches in 
length, with cutting head about one and three quarter inches wide 
and weight about four pounds. The second drill is shown by Fig. B; 
it is about twenty-seven inches long, one and eleven sixteenth 
inches wide on the cutting edge, and weighs about six pounds. 
The third or longest drill is shown at C; it is usually forty inches 
in length, cutting edge one and five eighth inches wide, and weighs 
about nine pounds. 

The scraper is shown by Fig. D. It is used to remove the sludge 
from the bottom of the hole, and consists of an iron rod one half 
inch in diameter, one end of which is flattened out in a circular 
form and turned up at right angles to the stem. The other end is 
made to terminate in a spiral hook or drag-hoist, the use of which 
is to withdraw the absorbent material used to dry the hole before 
inserting the explosive. 

The bull or claying-iron is shown by Fig. E. It is used for forc¬ 
ing clay into seamy rock and thus prevent the entrance of water 
into the blast-hole. It consists of a round bar of iron, called the 
stock or shaft, a little smaller in diameter than the bore-hole, and 
a thicker portion, called the head or poll, terminating in a striking- 
face. While this tool is not an essential part of a drilling outfit, 
yet it is a very serviceable one, and should always be at hand in wet 
ground when loose gunpowder is employed. 

Fig. F represents the tampmg-iron or rammer. It consists of a 
bar of copper or phosphor bronze, the tamping end of which is 
grooved to receive the fuse lying against the side of the bore-hole. 
The use of rammers made of iron is dangerous, as sparks produced 
by the striking of the iron against silicious substances may cause 
ignition of the charge. 

Fig. G represents an auxiliary implement called the beche. It 
is used for extracting a broken drill. It consists of an iron rod 
having a diameter slightly less than that of the bore-hole, and is 
made hollow at one end. The form of the aperture is slightly con¬ 
ical, so that it may pass over the broken stock of the drill, and when 
hammered down may grasp the stock in its higher portion with 
sufficient firmness to allow of the two being drawn out together. 




TOOLS ANI) MACHINERY EMPLOYED. 


623 



Fig. 216.—Hand-drilling Tools. 


Fig\G 




























































































624 


HIG11W AY CON ST RU CTION. 


Fig. H represents the sledge or striking-hammer; its form and 
weight are variable, the latter is usually about five pounds. 

Fig. I represents the hand hammer; its weight varies from two 
to four pounds. The distinction between a hammer and a sledge 
is founded on dimensions only; the hammer, being intended for use 
in one hand, is made comparatively light and is furnished with a 
short handle, while the sledge, being intended for use in both hands, 
is furnished with a much longer handle and is made heavier. 

Hand drills are used in sets of different lengths. The sets may 
be intended for use by one man or by two. In the former case 
the sets are described as “ single-hand ” sets, and they contain a 
hammer for striking the drills; in the latter case the sets are called 
“ double-hand,” and they contain a sledge instead of a hammer for 
striking. It may appear at first sight that there is a waste of 
power in employing two men, for that two men cannot bore as fast 
as one. This rate of speed can, however, be obtained, and is due 
less to the greater effectiveness of the stroke than to the fact that 
two men can, by repeatedly changing places with each other, keep 
up almost without intermission a succession of blows for an indefi¬ 
nite length of time, whereas with the single set the man is con¬ 
tinually obliged to cease for rest. 

The making and resharpening of the drills is an extremely 
important part of the blacksmith’s labor and requires judgment 
and intelligence. A smith will, with the assistance of a striker, 
sharpen and temper about thirty single-hand drills of medium size 
in an hour, or twenty double-hand drills of medium size in the 
same time. Of course much will depend on the degree of blunt¬ 
ness in the cutting edge; but assuming the drills to be sent up only 
moderately blunted, this may be taken as a fair average of the 
work of two men. 

PRICES OF HAND-DRILLING TOOLS. 


Drill-steel. .per pound $0.25 

Striking-hammers, 3 to 5 pounds.“ “ .36 

“ “ 5 pounds and over.“ “ .30 

Spoons..each 2.00 

Wedges.per pound .12| 

Plug and feathers.“ “ .30 

Crowbars ... .“ “ .10 

Stone-sledges.. . “ “ .30 

Blacksmith outfit.from $50 upwards 












TOOLS AND MACHINERY EMPLOYED. 


625 


Steam Drilling.— A steam-drilling outfit comprises a steam 
drill; a set of drill-steels; a set of blacksmith’s tools for sharpening 
the drills; a sand-pump; a band for centring piston; extra drill 
parts; a portable steam boiler; steam hose, etc. 



Steam drills vary in size, price, etc., as shown in the following 
table: 





DESCRIPTIVE TABLE OF DRILLS, FITTINGS, 


626 


HIGHWAY CONSTRUCTION. 


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TOOLS AND MACHINERY EMPLOYED. 


627 


PRICES OF STEAM-DRILLING TOOLS. 


Steam drill.$185.00 to $480.00 

Steam boiler .$230.00 to - 

Steam hose..54 to 97 cents per foot 

Drill-steels, per set. .$25.00 to $115.00 

Blacksmith’s swages for dressing drills.$15.00 

Forge and hand tools.. $50.00 upward 

Sand-pumps, each.$3.00 

Giant blasting-powder, per pound.15 to 60 cents 

Leading-wires, per foot..1 cent upward 

Magneto-electro blasting apparatus, each.$25.00 to $50.00 

Derricks, each...,.$100.00 upward 


Portable Boilers for operating steam drills.—Fig. 218 shows 
a convenient arrangement of a steam boiler for operating rock- 



Fig. 218.— Portable Boiler. 


drills. A water-tank occupies one end of the frame and fuel cart 
be carried on the other end. Price from $400 upwards. 





























































































































































628 


HIGHWAY CONSTRUCTION". 


1036. Tools Employed in the Construction of Broken-stone Roads 
—Stone-hammers.—T he hammers generally used for breaking 
stone are three, viz.: 

Sledges, 5 pounds and over...,. 30 cents per pound 

Hand hammers, 3 to 5 pounds. . 36 “ “ “ 

“ “ li to 2 “ . 45 “ 

The Ring-gauge, for testing the size of the stone and through 
which the largest stone should in all positions freely pass. The 
diameter is usually 2^ inches, can be made by any blacksmith at a 
cost of 25 cents. 

The Straight-edge, Fig. 219, is used for obtaining the proper 
transverse form of roads. It consists of a horizontal bar having in 
the centre of its length a plummet for ascertaining when the straight¬ 
edge is level. Gauges formed of upright pieces of wood marked off 
in inches are placed at every four feet; these upright pieces have a 
slot cut in them so as to allow of their being moved either up or 
down and adjusted to the desired depths below the horizontal line. 
These upright pieces are secured to the straight-edge, as shown in 
the section, by a small bolt passing through the slot in the upright 
and the straight-edge, the bolt being furnished with a thumbscrew, 
by tightening which the gauges are fixed in place when adjusted to 
the required depths. 



Lines.— Linen, in rolls 100 feet long; price per dozen rolls $9. 

Reel and Stake.— Price per dozen $6 to $9.50. 

Stone-forks. —The broken stone can be more easily and 
quickly taken up and thrown upon the roadway by the use of forks 
than by shovels. The price of forks ranges from $18 to $25 per 
dozen. 








































TOOLS AND MACHINERY EMPLOYED. 029 



Fig. 220.—Roadbed-roller, 


Roadbed-roller, Fig. 220.—This is a very efficient form of 
roller for compacting embankments and the subgrade surface of 
highways. The roller is 5 feet long with nineteen sections, ten 



Fig. 221.— Sprinkling-cart 



























































630 


HIGHWAY CONSTRUCTION. 


of 35 inches in diameter and nine of 32 inches in diameter, set 
alternately. The sections act dependency on the axle. Weight 
about 2^ tons. PTice $265. 

Sprinkling-carts. —Pig. 221 shows a convenient form of 
sprinkling-cart for use either on construction or sprinkling subur¬ 
ban streets and country roads. Capacity about 150 gallons. Price 
about $100. 

Rakes used for spreading the stone should be about twelve 
inches long and have prongs from two to three inches in length, 
spaced three quarters of an inch apart, and have handles about 
six feet long. The price of such rakes is from $12 to $15 per 
dozen. 

Stone-crushers. —The leading styles of stone-crushers are 
illustrated in Figs. 222 to 233. The dimensions, capacity, weights, 
etc., are given in the tables on pages 631, 632, and 633. 

The amount of the product in a given time will vary according 
to the character of the rock to be broken as well as to the size to 
which it is broken; the smaller the size the less the amount broken 
and the greater the power required. 

In getting an engine to drive a stone-crusher it is advisable to 
provide one of greater power than is stated in the tables, for no close 
estimate can be made to cover all varieties of rock, and it is more 
economical to use 10 H. P. from a 12 or 15 H. P. engine than from 
a 10 II. P. engine. 

For cost of crushing stone and cost of operating crushing- 
plants see Art. 365 et seq., and Table XXXIX. 

Portable Crushers. —Any one of the crushers described can be 
bad in portable form. Some are made portable by mounting on low¬ 
wheeled trucks, others by attaching travelling-wheels directly to the 
frame of the machine, and others by attaching a pair of wheels to one 
end to act as a front truck, using the fly- or balance-wheels of the 
machine as rear travelling-wheels. When the balance-wheels are used 
for this purpose, it is necessary to have independent belt-wheels. If 
the balance-wheels are used for belt-wheels, it will be necessary to 
have either a metal or wood covering which can be easily placed 
and removed, for the face of the balance-wheels will become too 
roughened to be used directly for belting. 



TOOLS AND MACHINERY EMPLOYED 


631 


BRENNAN CRUSHER. 


Size or Re¬ 
ceiving 
Capacity 

Approximate 
Product per 
Hour in Tons 
to Macadam Size. 

Approximate 

Weight. 

Proper 

Speed. 

Horse-power 

Required. 

Prices, 

5x20 

8 to 10 

7,000 

300 

8 


7x20 

12 “ 15 

10,000 

300 

12 to 15 

. 

8x 12 

8 “ 10 

8,000 

280 

8 


8 x 25 

15 “ 20 

13,000 

280 

15 to 20 


10x25 

20 “ 30 

16,000 

280 

. 20 “ 30 


12 x 37 

30 “ 40 

32,000 

260 

30 “ 40 


20x48 

60 “ 100 

72,000 

240 

80 



GATES CRUSHER. 




<D CG 

CD bt) 



.2 

.o 


o 

tx 

Space Occupied 

u 

0) 

1 

2 

03 J_- 

> o 

£ j 

O 

4ft 

i 

o 

t r. : 

Size. 

imensions of Ea 
Receiving Openii 
about. Inches. 

imensions of Tin 
Receiving Openir 
Combined, about. 

Inches. 

r eight of Breaker. 
Pounds. 

apacity per Hour 
Tons of 2000 1 

Passing 2*-in. Rii 
according to Ch 

acter of Rock 
Ore. 

evolutions of Drivi 
pulley. 

[eight from | 

Bottom cr 

rame to Top 
Hopper. = » 

eake 

ties. 

<M . 

O V 

-*_J Co 

ength of I* 

Frame. 

iameter of Hopp 
Inches. 

ize Engine Reco 
mended to D r i 
Breaker, Elevat 

and Screen. In 
cated Horse-powei 

rices Subject 

Change without I 
tice. 


Q 

ft 


£ 

O 




n 

ft 

£ 

a 

ft 

CO 



ft 


00 

2 x 4 

2 x 

12 

500 




700 


24 

17 

26 

13 

1 

to 

n 

$ 

125 

0 

4x10 

4 x 

30 

3,300 

2 

to 

4 

500 


50 

30 

73 

28 

4 

44 

5 


400 

1 

5 x 12 

5 x 

36 

5,600 

4 

It 

8 

475 


55 

31 

76 

421 

8 

44 

10 


600 

2 

6x14 

6 x 

42 

7,800 

6 

44 

12 

450 


61 

39 

90 

46J 

12 

44 

15 


800 

3 

7x15 

7 x 

45 

13,800 

10 

It 

20 

425 


75 

48 

103 

54* 

20 

44 

25 


1200 

4 

Rx 18 

8 x 

54 

21,500 

15 

(4 

30 

400 


91 

54 

114 

79* 

25 

44 

30 


1900 

5 

10x20 

10 x 

60 

27,000 

25 

44 

40 

375 


101 

63 

123 

88 

30 

4 4 

40 


2500 

6 

11 x24 

11 X 

72 

40,500 

30 

44 

60 

350 


114 

73 

139 

103 

40 

44 

60 


3500 

n 

14x30 

14 x 

90 

65,800 

50 

44 

125 

350 


144 

84 

145 

120 

75 

4 4 

125 


6000 

8 

18x42 

18x126 

89,000 

100 

44 

150 

350 


156 

90 

164 

132 

100 

(4 

150 


7000 


FORSTER CRUSHER. 


No. 

Open¬ 
ing in 
Jaws. 

Speed. 

Horse¬ 

power. 

Total 

Weight. 

1 

4 x 9 

350 

1 

1,800 lbs 

2 

5 x 15 

300 

3 

4,500 “ 

3 

7x18 

300 

5 

7.400 “ 

5 

12x24 

250 

8 

17,000 “ 


Capacity per 
Hour Varies ac¬ 
cording to 
Matter Crushed. 

Floor- 

space 

Required 

Price. 

Cost Extra 
Sets Dies, 
per Set. 

1 to 2 tons 

4* x 3* 

$ 190 

$10 

4 “ 7 “ 

6x4* 

390 

25 

5 “ 8 “ 

7 x 5* 

570 

35 

10 “ 14 “ 

11 x7J- 

1000 

90 












































































632 


HIGHWAY CONSTRUCTION 


FARREL CRUSHER. 


6 

Z 

Size or Receiving 
Capacity. 

Approximate Capacity in 
Tons, per day of 10 Hours, 
to Sizes Stated. 

Extreme 

Dimensions. 

Revolutions of 

Pulley. 

Horse-power 

Required. 

Total Weight. 

Price. 

Length. 

Breadth. 

Height. 



tons. in. 

tons. in. 

tons. in. 

ft. in. 

ft. 

in. 

ft. 

in. 



lbs. 


61 

15 X 9 

100 to 2£ 

80 to 2 

55 to 1| 

7 0 

5 

3 

5 

3 

275 

12 

15,000 

$ 750 

7 

16 X 10 

120 “ 2£ 

100 “ 2 

75 44 1J 

7 2 

5 

6 

5 

8 

275 

15 

16,200 

875 

8 

20 X 10 

175 “ 3 

150 “ 2£ 

125 “ 2 

7 8 

5 

10 

5 

1 

275 

20 

18,300 

1050 

*9 

24 X 15 

250 “ 3 

200 41 2i 

175 “ 2 

7 10 

7 

O 

<v 

5 

9 

275 

25 

26.000 

1575 

*10 

30 X 13 

300 “ 3 

275 “ 21 

225 44 2 

8 6 

8 

0 

/V 

6 

4 

275 

30 

37,600 

2250 

*11 

30 X 15 

400 “ 4£ 

350 “ 3£ 


8 6 

8 

2 

6 

4 

275 

30 

37 600 

2250 

*12 

36 X 20 

800 8 

600 “ 6 

500 to 5 

9 10 

8 

8 

6 

10 

275 

40 

50,000 

2875 

*13 

36 X 24 

1000 “ 10 

800 “ 8 


9 10 

8 

8 

6 

10 

275 

40 

50,000 

2875 


* These sizes have two driving-pulleys. 


CHAMPION CRUSHER. 


No. 

Size or Receiv¬ 
ing Capacity 
of Jaws. 

Product per 
Hour in Tons 
when Machine 
is Closed to 

2 Inches. 

Weight, 

Approxi¬ 

mated. 

Speed, 

Revo¬ 

lutions. 

Driving- 
pulleys, 
Diameter 
and Face. 

Horse¬ 

power 

Required. 

Price. 

8 

inches. 

7 X 13 

tons. 

7 to 13 

lbs. 

5,000 

180 

inches. 

44 X 8 

12 

$ 600 

4 

9 X 15 

12 “ 18 

8,000 

160 

50 X 8 

15 

800 

5 

11 X 26 

24 “ 36 

16,000 

150 

60 X 10 

25 

1500 


SMITH’S HYDRAULIC CRUSHER. 


Weight. 

Pounds. 

Capacity. 

Tons per Hour. 

Horse-power 

Required. 

Price. 

5,000 

9 to 12 

4 

$ 700 

7,000 

14 “ 18 

6 

850 

9,500 

20 “ 24 

8 

1100 

11,000 

25 “ 30 

12 

1500 



























































TOOLS AND MACHINERY EMPLOYED 


633 


WESTERN CRUSHER. 


No. 

Size or Receiv¬ 
ing Capacity 
of Jaws. 

Product 
per Hour. 

Weight, 

Approxi 

mated. 


inches. 

tons. 

lbs. 

5 

7 X 13 

10 to 12 

5,000 

10 

9 X 151 

12 “ 20 

8,000 

15 

10 X 22 

18 “ 25 

14,000 


Speed. 

Revo¬ 

lutions. 

Diameter and 
Face of Driv¬ 
ing-pulleys. 

Horse-pow r er 

Required. 


inches. 


200 

40 X 6£ 

8 to 10 

200 

44 X 8 

10 “ 12 

200 

44 X 10* 

15 “ 20 


AUSTIN CRUSHER. 


No. 

Jaw-opening 
in Inches. 

Size Engine 
Required. 

Speed. Revols. 

Weight of 
Crusher. 

Capacity per 
Hour. Tons. 

_ i 

Floor-space 

Required. 

Price. Not 
Mounted. 

Price. Mounted 
on Four-wheel 
Trucks. 

Price of Extra 
Dies. Per Pair. 

CO 

* 

8 X 15 
10 X 18 

10 H. P. 
15 “ 

300 

300 

6000 lbs. 
8000 “ 

10 to 14 
15 “ 20 

21 X 7 ft. 

3 X 8 “ 

$600.00 

900.00 

$ 725.00 
1050.00 

$40.00 

50.00 


Elevator, 14 ft. long, $175; for each additional foot add $5. Revolving screen, 2-sectiou, 
$200; 3-section, $250. Each section is 2£ ft. long by 2 ft. in diameter, made of steel, and 
turns on anti-friction rollers. 


BLAKE CRUSHER. 


Size or Receiv¬ 
ing Capacity. 

Product per Hour 
in Cubic Yards. 

Weight of 
Heaviest 
Piece. 

Total Weight. 

inches. 


lbs. 

lbs. 

10 X 4 

3 

1,695 

4,000 

8,000 

10 X 7 

5 

4,339 

15 X 9 

7 

6,500 

15,000 

20 X 12 

10-12 

10,000 

21,000 

20 X 15 

j Coarse or Pre- 1 
( liminary Breaker, f 

8,450 

32,600 

24 X 18 

9,425 

37,500 


Extreme Dimensions. 

Proper Speed. 
Revolutions. 

Horse-power 

Required. 

Price, f.o.b. 
Pittsburg. 

Length. 

Breadth. 

Height. 

ft 

in. 

ft. in. 

ft. in. 




3 

11 

3 3 

3 9 

250 

4 

$275 

5 

34 

3 8 

4 5 

250 

6 

450 

6 

5 

5 0 

5 11 

250 

9 

750 

r* 

i 

0 

5 6 

6 3 

250 

15 

1000 

8 

6 

5 0 

6 7 

150 

12 

. 

9 

10 

5 1 

6 10 

125 

12 

.... • • 




































































634 


HIGHWAY CONSTRUCTION 




Fig. 223.—The Brennan Crusher Sectional View. 


















































































































TOOLS AND MACHINERY EMPLOYED. 


635 



Fig. 224. —The Gates Crusher. Exterior View. 



Fig. 225. —The Gates Crusher. Sectional View 

















































































636 


HIGHWAY CONSTRUCTION 



Fig. 226.—The Forster Crusher. Sectional View. 



Fig. 227.—The Forster Crusher. 


Exterior View, 



































TOOLS AND MACHINERY EMPLOYED 


037 



Fig. 228.—The Farrel Crusher. Sectional View. 



Fig. 229.—The Champion Crusher. Sectional View. 










































































































































638 


HIGHWAY CONSTRUCTION", 



Fig. 230. —Smith’s Hydraulic Crusher. 


Fig. 231. —The Western 


Crusher. 


Sectional View. 















































































































































































































































TOOLS AND MACHINERY EMPLOYED. 


630 



\ j } 

/ V 

y / 


\y. 





Vt 

—a—r 
/ 

/ 

■ 4 1 "’ \\ 

/ i 

« 


Fig. 232.—The Austin Crusher. Sectional View. 



Screens. —Nearly all specifications for broken stone call for it to 
be screened, either to separate it into different sizes or to remove 
the tailings; for either purpose revolving screens made of steel 
plate perforated with holes of the required size are employed. They 
can be run in several ways, as shown in Figs. 237 to 241. 






































































































640 


HIGHWAY CONSTRUCTION”, 


Fig. 234 shows a three-section screen; the first section has holes 
one inch in diameter, the second section holes one and one half 
inches in diameter, and the third section holes two and one half 
inches in diameter. Holes of any other dimensions may be used, 
depending upon the sizes desired. Dust-jackets are also used in 
connection with the screens, thus separating the dust from the 
crushed stone. The following table contains the usual dimensions, 
weight, price, etc., of steel-plate screens: 


No. 

Diam¬ 

eter. 

Length, 
with three 
sections. 

Revolu¬ 
tions of 
Pulley. 

Size Pulley, 
Diameter 
Face. 

Weight, 

Lbs. 

Price for 
three sections 
complete. 

Price for 
two sections 
complete. 

1 

inches. 

24 

ft. in. 
10 6 

90 

inches. 

30 X 64 

2200 

$275 

$225 

2 

30 

12 

6 

90 

36 X 8 

3550 

385 

325 

3 

36 

12 

6 

80 

36 X 8 

3900 

450 

375 

4 

42 

12 

6 

70 

36 X 84 

4500 

550 

450 

5 

48 

15 

6 

GO 

42 X 9 

5500 

700 

575 

6 

54 

15 

C 

60 

48x10 

.... 

950 

800 



Fig. 234. —Revolving Stone-screen. 





































TOOLS AX I) MACHIXERY EMPLOYED 


641 



Fig. 235.— Semi-portable Engine and Boiler. 


Exgixes axd Boilers for Driyixg Rock-crushers are 
usually of the portable or semi-portable type. Fig. 235 shows a 
compact combination of the semi-portable form, and Fig. 236 shows, 
the portable type. 
























































































642 


HIGHWAY CONSTRUCTION - 



Fig. 236.—Portable Boiler and Engine. 

SPECIFICATIONS OF PORTABLE BOILERS AND ENGINES ON 

WHEELS. Fig. 236. 


No. of size . 

0 

1 

0 

3 

4 

5 

6 

r* 

i 

8 

Horse-power. 

6 

8 

10 

12 

15 

20 

25 

30 

35 

Diarn. of cylinder, in . 

5 

5 

6 

7 

8 

8 

9 

10 

10 

Length of stroke, in.. 

8 

8 

9 

10 

10 

12 

12 

12 

15 

Usual no. revolutions. 

185 

240 

190 

100 

160 

170 

170 

170 

150 

Diam. of pulleys, in.. 

14&32 

14&32 

1G&36 

20&44 

20&44 

30&48 

32&54 

32&54 

36&G0 

Face of pulleys, in.... 

Sl& 8.1 

82 & 8 I 

8^&9^ 

10i&10F 

10^&10i 

8.i&12£ 

10.J&12* 

101&12J 

104& 14.. 

Diam. of boiler, in- 

26 

28 

30 

32 

32 

34 

36 

36 

40 

Length of furnace, in. 

34 

36 

38 

38 

44 

52 

52 

52 

52 

Height of furnace, in. 

30 

32 

31 

38 

38 

38 

40 

40 

44 

■Width of furnace, in.. 

21 

22 

24 

26 

26 

28 

30 

SO 

34 

No. of 3-inch tubes_ 

17 

20 

22 

26 

26 

30 

34 

34 

40 

Length of tubes, in... 

54 

66 

72 

72 

78 

90 

96 

102 

102 

Shipping wt.complete 

4800 

5000 

5700 

6000 

7100 

8100 

9500 

10,500 

11.300 

Price. 

$700 

$724 

$788 

$880 

$931 

$1045 

$1085 

$1,277 

$1,351 


Stone-crushing Plants.— Complete crusliing-plants include 
a stone-crusher, engine, boiler, shafting, pulleys, and belting. These 
plants maybe divided into two classes, viz., stationary and j portable . 
In arranging either class of plant care must be taken to save un¬ 
necessary handling of the stone; to this end the crusher must be 



























































TOOLS AND MACHINERY EMPLOYED. 


643 


placed (1) so as to receive the stone directly from the carts or other 
conveyance used to transport it from the quarry, and (2) so as to 
deliver the broken stone into the vehicles which are to haul it away 
without handling. 



Fig. 237.—Crushing-plant for Hillside Location. 



Fig. 238. —Crushing-plant for Level Ground. 


In Figs. 237 to 240 a few illustrations are presented showing 
simple methods of arranging plants. Fig. 237 shows a fixed plant 
for hillside location, with road graded for delivery of stone to the 
crusher, and chute for delivery of broken stone to the carts. 

Fig. 238 shows a fixed plant for location on level ground, with 
road graded for delivery of stone to crusher, and elevator for rais¬ 
ing crushed stone to chute for delivery into carts. 




























































































































































































































































644 


HIGHWAY CONSTRUCTION, 


Fig. 239 shows a plant for temporary use, with platform for re¬ 
ceiving the stone to be crushed, three-section screen, and platform 



Fig. 239.—Temporary Crushing-plant. 



Fig. 240.—Portable Crushing-plant. 


foi leceiving the crushed and screened stone, from which it can be 
shovelled into the carts or an elevator can be attached. 

^ ig. ^40 shows a portable plant with elevator and screen. 
















































































































TOOLS AND MACHINERY EMPLOYED. 


G45 



Jig. 241 shows a portable plant with crusher elevated sufficiently 
to allow of a screen being used without the employment of an ele¬ 
vator. 


Fig. 241.—Crusher Mounted on Wheels. 

Stone-distributing Carts.— The cart shown in Fig. 242 is 
specially designed for distributing broken stone for building or re¬ 
pairing roads. The cart is mounted on four wheels, so arranged 
that it can be turned in a short space. The bottom of the cart 
slopes downward to the back, and the tail-board is hinged at its 
upper edge and is furnished with two adjusting chains by which 
the opening or swing of the lower edge is regulated. Steel wings are 
attached to the sides of the cart at the tail-board for the purpose of 
spreading the stone the full width between the wheels. The cart 
is tilted by a rack and pinion operated by the driver, and may be 
fixed at any desired angle. As the stone flows from the rear of the 
cart it is levelled by a scraper attached to the bottom of the tail¬ 
board; this scraper is pivoted at the centre and can be adjusted so 
as to spread the stone to any required thickness and over any de¬ 
sired width equal to or less than the gauge of the cart, and thicker 
on one side than on the other. 

The carts are built in two sizes, to be hauled by two or three 
horses, respectively, the horses oeing harnessed abreast. The two- 





646 


HIGHWAY CONSTRUCTION", 


horse size is five feet wide and has a capacity of one and one half 
cubic yards, and weighs empty 2250 pounds. The three-horse size 
is seven feet six inches wide and has a cajiacity of two and one half 
cubic yards, and weighs empty 2750 pounds. 

The price of the two-horse cart is $175, and of the three-horse 
size $200. 



Horse Rollers. —The following figures show a few selections' 
from the large variety of horse rollers in the market. The principal 
dimensions, weights, and prices are given on pages 647 and 648. 



Fig. 243. —Enterprise Roller. 




























































































































TOOLS AND MACHINERY EMPLOYED. 


647 


For the advantages of rolling, form of rollers, amount of rolling, 
etc., see Articles 396, 397, and 400. 

The Enterprise Roller, Fig. 243.—The standard dimen¬ 
sions of this roller are: Diameter of main roll 50 inches, made in 
two sections, each 26 inches wide, giving a rolling width of 52 
inches; the standard weight is 4 tons, hut the ballast-box may be 
filled with stone and thus loaded to 6 or 8 tons. Price about $100 
per ton. 

Pope’s reversible roller, Fig. 244, is made in sizes ranging from 
5 to 10 tons. The diameter of the 5-ton roller is 5 feet, and width 



Fig. 244.— Pope’s Reversible Roller. 


5 feet. The diameter of the 10-ton roller is 7£ feet, and width 
5 feet. Price $100 per ton. 

The Champion reversible roller, Fig 245, is constructed in two 
sections which revolve independently on the axle. The diameter 
of the rolls and width of the rolling face are the same, viz., 5 
feet. This roller is made in four weights, viz., 2£, 3|r, 4£, and 5| 
tons, and each is supplied with two steel boxes, each of which will 
hold about a ton of pig iron, thus converting each roller from a 
light- to a medium- or heavy-weight roller, as desired. Price 2| 
tons $350; for each additional ton add $50. 





648 


HIGHWAY CONSTRUCTION. 


The Austin roller, Fig 246, is made in weights of 3J, 4, and 41- 
tons. The rolls are 4J feet in diameter, and width 5 feet. 



Fig. 245.— Champion Reversible Roller. 



Fig. 246. —Austin Reversible Roller. 


Steam Rollers.— There is a large variety of steam rollers in 
the market from which to select. The leading types are shown in 

kigs. 247 to 151, and the principal dimensions, etc., are given in 
the following tables. 

For the advantages of rolling, cost of maintaining steam rollers, 

and amount of rolling required, etc., see Articles 396, 398, 403, and 
404. 








































TOOLS AND MACHINERY EMPLOYED. 


649 


THE SPRINGFIELD ROLLER. FIG. 247. 



10-ton. 

12J4-ton. 

15-ton. 

Front roll, diameter. 

4 feet 

4 feet 

4 feet 

Front roll, width. 

44 inches 

48 inches 

48 inches 

Driving-wheels, diameter. 

6 feet 

6 feet 

6 feet 

Driving-wheels, width. 

18 inches 

20 inches 

22^ inches 

Extreme width of machine... 

75 inches 

85 inches 

90 inches 

Pressure per inch of width. 

500 pounds 

570 pounds 

600 pounds 

Coal capacity. 

450 pounds 

500 pounds 

550 pounds 

Water capacity. 

Maximum grade ascended with 

153 gallons 

175 gallons 

200 gallons 

100 pounds steam. 

1G per ct. 

16 per ct. 

16 per ct. 


THE PITTS ROLLER. FIG. 248. 


Front roll, diameter.. 

Front roll, width. 

Driving-wheels, diameter. 

Driving-wheels, width. 

Extreme width of machine. 

Wheels, base... 

Coal capacity. 

Water capacity... 

Coal consumption per day varies ac¬ 
cording to work and grades from... 
Travelling speed per hour with fast 

gear..... 

Travelling speed per hour with slow 
gear.. 


12^-ton. 

15-ton. 

46 inches 

48 inches 

51 inches 

52£ inches 

69 inches 

72 inches 

20 inches 

22 inches 

89 inches 

94 inches 

128 inches 

133 inches 

500 pounds 

500 pounds 

275 gallons 

320 gallons 

600 to 1000 lbs. 

800 to 1200 lbs. 

2f miles 

2f miles 

2 miles 

1.85 miles 


THE HARRISBURG ROLLER. FIG. 249. 


- 

10-ton. 

12-ton. 

15-ton. 

Drivino-.wheels width. 

18 inches 
466 pounds 
400 pounds 
130 gallons 

20 per ct. 

20 inches 
500 pounds 
500 pounds 
155 gallons 

20 per ct. 

22 inches 
566 pounds 
600 pounds 
180 gallons 

20 per ct. 

Pressure per inch of width. 

Coal caoacitv. 

Water caoacitv.. 

Maximum grade ascended with 
120 oounds of steam . 

























































650 


HIGHWAY CONSTRUCTION". 


THE AVELING & PORTER ROLLER. FIG. 250. 



10-ton. 

# 

15-ton. 

20-ton. 

Front roll, diameter. 

45 inches 

48 inches 

54 inches 

Driving-wheels, diameter. 

66 inches 

72 inches 

78 inches 

Extreme width of machine .... 

78 inches 

87 inches 

96 inches 

Pressure per inch of width. 

450 pounds 

550 pounds 

650 pounds 


approx. 

approx. 

approx. 

Coal capacity. 

400 pounds 

450 pounds 

500 pounds 

Water capacity. 

Maximum grade ascended with 
100 pounds of steam on bin of 

150 gallons 

200 gallons 

250 gallons 

loose metalling.. 

17 per ct. 

17 per ct. 

17 per ct. 


THE COLUMBIAN ROLLER. FIG. 251. 



27,000 lbs. 

32,500 lbs. 

38,000 lbs. 

Front roll, diameter. 

48 inches 

48 inches 

52 inches 

Driving-wheels, diameter. 

70 inches 

72 inches 

74 inches 

Driving-wheels, width. 

20 inches 

22 inches 

24 inches 

Extreme width of machine.... 

81 inches 

87 inches 

95 inches 

Coal capacity ) 

Water capacity f 

sufficient 

for 5 

hours 

Compression of drivers per 
square inch. .. 

507 pounds 

575 pounds 

605 pounds 

Grade ascended.. 

* 

14 to 20 

feet per 

100 



Fig. 247.— The Springfield. 





























































































TOOLS AXI) MACHINERY EMPLOYED 


651 



Fig. 248 —The Pitts. 



Fig. 249. —Tiie Harrisburg, 







































































































652 


HIGHWAY CONSTRUCTION - , 



PlG. 250. —The Aveling- & Porter. 



Fig. 251. —The Columbian - . 


















































TOOLS AND MACHINERY EMPLOYED. 


653 


1037. The Tools employed for the Maintenance of Broken-stone 
Roads are: 


Shovels . 



7.00 to $13.50 

Picks.. 


< t a 

10.75 “ 

22.50 

Spades. 


tt i t 

13.25 “ 

14.50 

Hoes. 


tt 11 

13.50 


Rakes. 


tt i i 

14.00 to 

16.00 

Hand rammers... 



1.15 “ 

12.00 

Wheelbarrows.. .. 



20.00 “ 

52.50 

Brush-hooks. 


11 it 

17.00 


Axes. 


tt t t 

12.00 to 

15.50 

Scrapers. 



8.00 “ 

12.00 

Brooms . 



8.50 “ 

9.00 

Stone-sledges. 


. per pound 

.30 


Stone-hammers .. 


i t (i 

.45 to 

.30 

Grass-shears . 



1.63 “ 

2.63 

Turfing-axes . 


( c 

1.75 


Sod-lifters . 


l 4 

2.75 


Straight-edges. .. 


t t 

12.00 


Drain-cleaners - 



9.00 to 

11.00 

Levels . 


tt i t 

48.00 


Lines . 


tt a 

9.00 



1038. Tools Employed in the Construction of Block Pavements— 

Hand Hammers. —Cobblestone-hammer, Fig. 252, price $2.50 each. 
Square-block hammer, Fig. 253, price each $2.50. 
Brick-hammer, Fig. 254, price each $1.50. 




Fig. 252. 


Fig. 253. 



Fig. 254. 


Pavers’ crowbars, per pound 12 cents. 

Sand-screens, from $6 to $12 each. 

Brooms, rattan and wire, $4 to $8 per dozen. 

Hand Rammers. —Hand rammers are of different forms, as 

shown in Figs. 255 to 259. 

Fig. 255, used for cobblestones, is of wood, generally locust, 
banded with iron, weighs about 40 lbs.; price $4 to $7.50. 




























654 


HIGHWAY CONSTRUCTION". 


Fig. 256, used for Belgian blocks, ,is of wood and steel, weighs 
about 45 lbs.; price $9. 

Fig. 257, used for granite blocks, is made of iron, with cast- 
steel face, locust plug, and hickory handles, weighs from 45 to 55 
lbs.; price $9 to $12. 


Fig. 255. 



Fig. 256. 



Fig. 257. Fig. 258. 



Fig. 259. 



Fig. 258, used for brick, is made of wood, shod with cast iron or 
steel, weighs about 27 lbs.;-price $3. 

Fig. 259 is used for miscellaneous work, as tamping in trenches 
and next to curbs, weighs about 20 lbs.; price $1.15 to $3. 

1039. Tools Employed for Asphalt Pavements.—The tools used 
in laying asphalt pavements comprise iron rakes, hand rammers and 













































































TOOLS AND MACHINERY EMPLOYED 


655 


smoothing-irons, hand rollers, either with or without a fire-pot, and 
steam rollers, either with or without provision for heating the front 
roll. 

The tamping- and smoothing-irons are shown in Figs. 260 and 
261. They are of cast iron, with wood handles. They are used 
hot, being heated in the portable fire-box shown in Fig. 263. They 
cost about $20 per dozen. 



Fig. 262.—Fire-pot Roller. 



Fig. 263.—Portable Fire-box. 


Fig. 262 shows a hand roller, with fire-pot; it is of cast iron, with 
a smooth-turned face, usually 3 feet in diameter and 3 feet wide. 
The weight varies from 400 to 1000 lbs., and the price is about 10 
cents per pound. 

The steam rollers used for compressing and smoothing asphalt 
and plastic pavements are different in construction, appearance 



























































G5G 


HIGHWAY CONSTRUCTION. 


and weight from those employed for compacting broken stone. 
The difference is due to the different character of the work re- 




Fig. 265.—Asphalt-roller. 


quired: In compacting broken stone the solidification is mechan¬ 
ical and is effected by the weight or pressure of the machine; in 






































TOOLS AND MACHINERY EMPLOYED. 


657 


the case of 'asphalt and plastic pavements the solidification is 
effected by chemical action, the roller being only required to bring 
the constituents into more intimate contact and to produce a 
smooth surface. 

Figs. 264 and 265 illustrate the form of roller used for 
asphalt and plastic pavements; the weight is usually five tons, but 
they are made in sizes ranging from three to fifteen tons; the rear 
drum or roller is usually made with solid heads, so that it can be 
filled with water or sand and thus increase its weight. 

There are several of these rollers on the market to select from; 
they all agree in the principle of construction, differing only in 
minor details and dimensions. 



Fig. 266.— Asphalt-mixing Machine. 


The principal dimensions of a five-ton roller are as follows : 


Front roll or steering-wheel 
Rear roll or driving-wheel: 

Width of front roll. 

“ “ rear “ . 

Extreme length. 

“ height . 

Water capacity. 

Coal “ . 


30 to 32 inches diameter 
48 “ 

40 

40 “ 

.14 feet 

.7 to 8 feet 

. 80 to 100 gallons 

.200 pounds 


The price for a five-ton roller and heavier is about 8400 per ton. 

























658 


HIGHWAY CONSTRUCTION. 


Asphalt-mixers. —The general form of the machines employed 
for mixing the materials for asphaltic cement pavements is shown 
in Fig. 266. The cut shows an engine attached to the machine, 
but this can be omitted and the power applied by belting, using 
either spur or bevel gearing to suit location. 

The machines are made in various lengths and diameters and 
with and without steam-jackets. 

A steam-jacketed mixer 30 inches diameter and 8 feet long, 
with a capacity of about 5 cubic yards per hour, costs about $325. 

Surface-heater for Repairing Asphalt Pavements.— 
Fig. 267 shows the Perkins surface-heater for repairing asphalt 
and mastic pavements. It consists of a metal tank mounted on 
wheels, and at the rear of this a series of burners surrounded by a 
wire netting packed with asbestos cement. The tank, which has a 
capacity of about half a barrel, contains gasoline. An air-pump at 



Fig. 267.—Surface-heater. 


the head of the tank is used to force the gasoline to the burners, 
e purpose of the asbestos packing is to conserve and diffuse the 
eat. Each burner can be turned on and off at will, and when all 
ire in use the tank w r i 11 keep them running for about five hours. 
The machine complete weighs about 700 pounds. 

The method of operation is to place the heater over the space 
to be repaired and turn on the heat. In a very short time the 







TOOLS AND MACHINERY EMPLOYED. 


659 


entire surface of the pavement under the hood is softened, so that 
the top can be removed with a hoe. Only sufficient of the old 
material is taken off to secure a clean, fresh surface, which, being 
hot, the new material welds perfectly with it. 

Concrete-mixing Machines. —Where large quantities of con¬ 
crete are required, as in the foundations of improved pavements, con¬ 
crete can be prepared more expeditiously and economically by the use 
of mechanical mixers and the ingredients will be more thoroughly 
mixed than by hand. Thorough incorporation of the ingredients 
is an essential element in the quality of a concrete; when mixed by 
hand, the incorporation is rarely complete, because it depends upon 
the proper manipulation of the hoe and shovel. The manipulation, 
although extremely simple, is rarely properly performed by the or¬ 
dinary laborer unless constantly watched by the overseer. Several 
varieties of concrete-mixing machines are in the market. A con- 



Fig. 268 .— Concrete-mixing Machine. 


venient portable type is illustrated in Figs. 268 and 269. The 
capacity of the mixers ranges from five to twenty cubic yards per 



























660 


HIGHWAY CONSTRUCTION. 


hour, depending upon size, regularity with which the materials are 
supplied, speed, etc. In price they range for machines without 
engines from $425 to $600 ; with engines, from $950 to $1250. 

For the advantages of concrete, cost, etc., see Articles 45 ? et 

seq. 



Fig. 269. —Concrete-mixing Machine. 


Sand-dryers. —Revolving cylinders connected to a furnace 
are employed for drying the sand used, for the cushion coat of 
block pavements, for mixing with asphaltic cement, and for heat¬ 
ing the gravel used to fill the joints in block pavements. They are 
made in various forms and sizes; the one shown in Fig. 270 is 15 
feet long and 3 feet in diameter and has a capacity of 5 cubic 
yards per hour. Price $600. 

Revolving cylinders mounted on wheels, 9 feet long and 2 feet 
in diameter, cost about $250. 

Rectangular dryers mounted on wheels, 9 feet long, 4 feet wide, 
and 4 feet deep, cost about $150. 

Pans 6 feet long, 5 feet wide, and 6 inches deep cost about $20. 





















TOOLS AND MACHINERY EMPLOYED 


C61 






Fig. 271. —Portable Heater for Asphalt or Paving-cement. 


Fig. 270. —Sand-dryer. 



























































662 


HIGHWAY CONSTRUCTION. 


Heating-kettles are employed for heating the paving-cement 
used for filling the joints in block pavements, and for heating the 
asphalt paving mixture for asphalt pavements when it has to be 
conveyed long distances from the factory. They are made in 
various forms and sizes. Circular ones are usually about 3 feet 6 
inches in diameter and 3 feet 6 inches high, with the melting- 
chamber 20 to 24 inches deep, and cost about $60. The rectangular 
ones range from 4 to 8 feet in length and from 3 to 4 feet in 
width and from 2 to 4 feet deep at centre of heating-chamber; they 
range in price from $75 to $500. The most approved form is 
shown in Fig. 271. It is constructed with double bottom, similar 



Fig. 272.— Sweeping Machine. 


to a double boiler, so that the heating-surface extends the full 
length and well up on the sides. The melting-chamber is made of 
soft steel. Capacity about 600 gallons; weight with tongue, double- 
tree, and neck-yoke 3320 lbs. 

1040. Tools for Cleansing— Hand Tools.— Brooms for street 
sweeping are made of steel wire or rattan; their size is generally 16 
inches long by 4 inches wide; wire lasts longer than rattan, but is 
only suitable for block pavements. 


Price, steel.per dozen $12.00 to $18.00 

“ rattan . “ “ 8.50 “ 9.00 


Squilgees, or rubber scrapers, are used for cleaning asphalt 
pavements. Price per dozen $7.50 to $9. 



















































































































TOOLS AND MACHINERY EMPLOYED. 


663 


Mechanical Sweepers. —A variety of these machines are in 
the market, and in various sizes, to he used with one or four horses. 
Figs. 272 to 276 show a few of the many forms. 

The sweeper shown in Fig. 272 is known as the “ Pride of New 
York.” The broom is 8 feet 6 inches long, and sweeps a track 7 



Fig. 273. —Sweeping Machine. 



Fig. 274. —Sweeping Machine. 


feet 10 inches ; it weighs complete 1900 lbs., and is operated by 
two horses, and costs about $400. Smaller machines of the type 
are also manufactured, to be operated by one horsey the one- 
horse machine sweeps a track 5 feet 6 inches wide, weighs 1400 
lbs., and costs about $300. 























664 


HIGHWAY CONSTRUCTION. 


Fig. 273 shows the “ Austin Sweeper.” It is made of steel 
throughout. The broom is 8 feet in length and is made of tem¬ 
pered flat steel wires or rattan, and sweeps 6 feet wide. It is 
operated by two horses. 

The sweeper shown in Fig. 274 is known as the “ Barnard 
Castle.” It is made in England, and is extensively employed both 



Fig. 275.—Combined Sweeper and Sprinkler. 



Fig. 276.—Combined Sweeper and Sprinkler. 


in that country and in America. It is manufactured in two sizes, 
viz., to sweep six feet and seven feet six inches, respectively. The 
smaller machine is made either with shafts for one horse or with a 
pole for two horses. The larger machine is made only with a pole 
for two horses. 

















































TOOLS AND MACHINERY EMPLOYED. 


665 


Combined Sweeper and Sprinkler, Figs. 275 and 276, is 
designed for cleansing either stone, wood, or asphalt pavements. 
The machine consists of a circular water-tank with a revolving 
brush beneath it. A water-pipe or spreader travels in advance 
of the brush and facilitates its operation. 



Fig. 277.— Scraping Machine. 

Scraping Machines.— For the removal of stiff mud and snow 
from pavements scraping machines are extensively employed. 
They generally consist of a number of steel or iron teeth, three to 
five inches wide, attached to a frame in such manner that they 
will rise and pass over any fixed obstacle without suffering injury.. 

Fig. 277 illustrates the Barnard Castle street-scraper. It is 
drawn by either one or two horses, and delivers the mud or snow 
one side in ridges, similar to the sweeping machine. The extent of 
surface scraped per hour by one of these machines is about 8000 

square yards. , 

Figs. 278 to 280 illustrate two forms of the hand-cart used m 

cleaning streets by the “patrol,” or block system. Price $25. 




























666 


l 


HIGHWAY CONSTRUCTION. 



Fig. 278.— Patrol-cart. 





Fig. 279.—Patrol-cart. 










































































































































































































TOOLS AND MACHINERY EMPLOYED. 667 



Fig. 280. —Patrol-cart. 


Fig. 2SI shows the hand scoop used by the street patrol in 
several cities. 



Fig. 281.—Hand Scoop. 


















































































668 


HIGHWAY CONSTRUCTION' 


Fig. 282 represents a hand sweeping machine which can be 
operated by one man. Price $65. 



Fig. 282.— Hand Sweeper 


Dump-carts. — The cart used to remove street-sweepings is 
shown in Fig. 283. The body is iron, and the usual dimensions are 
seven feet long, three feet eleven inches wide, and two feet six 
inches deep, and capacity one and one half tons. 



Fig. 283.—Dump-cart. 



























































TOOLS AND MACHINERY EMPLOYED. 


669 


Combined Sweeping and Collecting Machine. —In conse¬ 
quence of the increasing use of improved pavements, and with the 
view of 1 educing the amount of manual labor required with the 
usual form of side-sweeping machines, inventors have sought to 
devise machines which will, instead of merely sweeping the dirt 
into windrows, collect and pick it up. Three types of “pick-up” 
machines are now on the market, viz., the “ International,” the 
“Universal,” and the “Pneumatic.” 

The International machine (Figs. 284 and 285) consists of an 
iron collecting-box and a revolving broom. The box has hinged 
sides and bottom, and is open at the back to receive the dirt 
brushed up by the broom. The broom is entirely enclosed, and the 



Fig. 284. —Sweeping and Collecting Machine. 


back part of the casing forms a receptacle for dirt carried over by 
the broom, and which would otherwise be deposited upon the sur¬ 
face already swept. The operation resembles that of an ordinary 
carpet-sweeper. 

The machine is made of iron and steel, is mounted on four 
wheels, and is drawn by two horses. The broom is 5 feet long, 
and revolves on a stationary spindle running through a tube in the 


























































670 


HIGHWAY CONSTRUCTION. 


centre of the broom. Medium-coarse bass is used for the broom, 
and its life is from 18 to 25 days. The collecting-box has a ca¬ 
pacity of one cubic yard, but it cannot be filled to its capacity, as 
the dirt would fall back upon the broom, and, in fact, the dirt has 
a tendency to form a ridge near the open end of the box, which 
prevents the entrance of fresh dirt carried up by the broom, so 
that the box has to be dumped frequently in order to prevent the 
dirt from dropping back on the street. 



Fig. 285. —Sweeping and Collecting Machine. 


The machine weighs about 2500 pounds, sweeps within one 
foot of the curb, and the driver can regulate the pressure of the 
broom on the pavement or throw it out of gear. 

This machine has been successfully used for collecting and pil¬ 
ing the dirt swept to the side of the street by an ordinary side¬ 
sweeping machine. When used in this way, it is said it saves 
the cost of three gutter-men, and half the teams for hauling off 
the sweepings, as the wagons can be loaded much more quickly on 
account of the piling of the dirt. 

The Universal machine (Fig. 286) consists of an iron frame 
carrying a diagonal revolving broom, 26 inches in diameter, which 
sweeps the dirt into a windrow. Directly in line with this wind¬ 
row, and behind the delivering-end of the long broom, is a short 
broom, 31 inches in diameter and 2 feet wide, which revolves at 
two and a half times the speed of the main broom, and drives the 


































TOOLS AND MACHINERY EMPLOYED. 


671 


material of the windrow into a chamber at the base of an endless- 
belt elevator, the buckets of which carry up the dirt and dump it 
into a chute, through which it falls into a covered bin mounted on 
the frame of the machine. This bin is carried by trunnion bear¬ 
ings at each end, and when full a dump cart is driven alongside the 
machine, and the bin is tilted by means of a crank-handle and 
gearing to discharge its load into the cart. 



Fig. 286.— Sweeping and Collecting Machine. 


The machine weighs about 4000 pounds, and is drawn bv three 
horses; the capacity of the bin is about one cubic yard. If worked 
steadily without delays, the machine can sweep about a mile of 
street an hour. 

This machine has been successfully tried in New York and 
Boston, and Mr. II. H. Carter, M. Am. Soc. C. E., Superintendent 
of Streets, Boston, states that it has demonstrated its ability to do 
the work at about 45 per cent of the cost under the former method, 
by which the dirt was swept into windrows by ordinary side-sweep¬ 
ing machines, then swept by hand into piles and shovelled into 
dump-carts. 

The Pneumatic machine works by an air-blast. It consists of 
an iron box 6| feet wide, 10 feet long, and feet from the ground 
to the top, mounted on four wheels, and equipped with an exhaust 
fan operated by a 5-liorse-power engine, and rectangular brushes or 
scratchers. It is operated by two men and three horses, and in 
working order weighs about G000 pounds. 

In operation the scratchers drag on the street and loosen the 












672 


HIGHWAY CONSTRUCTION 


dirt, which is carried by the air-blast into the dirt-box. The ex¬ 
haust steam is used to dampen the dirt, and any dust that may be 
picked up is carried to the furnace of the boiler. The dirt-box has 
a capacity of about half a cubic yard, and when full is dumped, 
leaving the material in convenient piles for shovelling into the 
dump-carts. 

Sprinkling-carts are made in various sizes, and of wood, iron, 
and steel, and with various devices for controlling and spreading 
the water. 

The sprinkler shown in Fig. 287 is made in the following sizes: 


Price. 

1000 gallons.$550.00 

750 “ 475.00 

550 “ 425.00 

650 “ 400.00 



Fig. 287. —Street-sprinkler. 


big. 288 shows a sprinkler made entirely of steel. Three sizes 
are on the market, viz., GOO, 750, and 1000 gallons. 

Snow-ploughs.— The ploughs employed for the removal of 
snow on country highways are usually made of wood. The general 
form is shown in Figs. 289 and 290. They are loaded with stone. 












































































TOOLS AND MACHINERY EMPLOYED 


673 


In light falls, say of 6 inches, one horse is sufficient, but in deeper 
falls two or more are necessary. 



Fig. 288.— Street-sprinkler. 


Snow-shovels.per dozen $4.50 

Sidewalk-chisels. “ $7.00 to $17.00 






Sffn 


Side View. 


-0E& 



Side View. 


























































































674 HIGHWAY CONSTRUCTION. 


1041. Tools Employed for Artificial Stone Pavements.— 

Tampers (Fig. 291). —Oast iron, with hickory handle; range from 
6x8 inches to 8 X 10 inches. Price from $2 to 12.50 each. 




Fig. 293. 



Fig. 295. 


Fig. 294. 











































TOOLS AND MACHINERY EMPLOYED 


675 


Quarter-round, Fig. 292, is used, for rounding corners and 
sedge. Made of any desired radius. Price from $1.75 to $3 each. 

Jointer, Fig. 293, is used for trimming and finishing the joints. 
Price from $2 to $3 each. 

Cutter, Fig. 294, is used to cut the concrete into blocks. 
Price $3 each. 



Fro. 298.— Cast-iron Catch-basin. 


Gutter-tool, Fig. 295, is used for forming and finishing gutters. 
Price $2.50 each. 

Imprint-rollers. —Figs. 296 and 297 show two designs of 
rollers for imprinting the surface of artificial stone pavements with 
grooves, etc. Price ranges from $8 to $15 each. 

















































































































































































































































































































676 


HIGHWAY CONSTRUCTION. 


1042. Catch-basins, Sewer Inlets, and Gutter-crossings.— Fig. 

298 illustrates a catch-basin made of cast iron, which is introduced 
as a substitute for the brick chambers now generally used. It is 
easily put together without skilled labor, and each piece or section 
is light enough to be handled readily. The front opening is 1 foot 
high and 4-j feet wide, protected by a wrought-iron grating, so 
formed that floating refuse will not lodge and close the opening. 
Price, corner inlet $125; side inlet $115. 

Fig. 299 shows a catch-basin cover and grating for use as a side- 



Fig. 299. —Side Inlet. 


inlet. The grate-opening is 12 X 24 inches. The lid or cover for 
removing sediment is 24 inches in diameter. Price $16. 



Fig. 300. —Gutter-grating. 


Fig. 300 shows a cast-iron gutter-box designed to fit into the 
hub of a 10-inch sewer-pipe, and is suitable for use on highways. 






























TOOLS AND MACHINERY EMPLOYED. 


677 


park walks and streets. Dimensions on top, 9 inches long, 6 inches 
wide, and 3 inches deep; total height, 4^ inches; weight about 20 
pounds. Price $2.50. 

Among the appliances invented for the purpose of closing the 
street inlets to sewers against the escape of gases, etc., may be 
mentioned the Hitchcock patent sewer inlet-trap (Fig. 301). The 



Fig. 301. —The Hitchcock Sewer Inlet-trap. 



Fig. 302. Fig. 303. 


device explains itself; the purpose is to prevent the escape of 
gases from the sewer during the cooler seasons, when the air in the 
sewer is usually warmer than the air in the streets. The lid A 
opens and permits the discharge of water entering the inlet; but at 



































































































































































678 


HIGHWAY CONSTRUCTION". 


other times it remains tightly closed by its own weight against the 
fixed spout D. The trap is made of cast iron, and has been suc¬ 
cessfully used in Springfield, Mass., for about fifteen years. The 
price is about $4.50; including the grate and rim, which is 18 
inches in diameter and weighs about 175 pounds, the price is $9. 


Figs. 302 and 303 show a cast-iron inlet and manner of setting 
designed for conducting storm-water from the side ditches of im¬ 
proved suburban or country roads into the under-drains. 



Fig. 304. — Gutter-crossing. 



Fig. 305. —Gutter-crossing Plate. 


The inlet-head is of cast iron, with a removable grate of wrought 
iron, which is placed at an angle of 60 degrees, to correspond with 
the slope of the bank. It is provided with flanges to rest upon a 
brick or stone foundation, is circular in form and 18 inches in 
diameter, and can be reduced to fit any desired size of pipe. Price, 
without reducer, $6; with reducer, $7. 

Figs. 304 and 305 show two forms of gutter-crossings. Fig. 302 






























TOOLS AND MACHINERY EMPLOYED. 


679 


is made m widths from 4 to 26 inches, and from 4 to 10 inches in 
depth, and in lengths from 3 to 6 feet. Price per foot ranges from 
$1.30 for the smaller sizes to $7.60 for the larger. Fig. 303 is 
made in sections 30 inches wide and 5 feet long. Price $12 each. 



Fig. 306.— Gutter-boxes and Gratings. 


Pig. 306 shows cast-iron gutter-boxes and gratings for use with 
catch-basins. They are made in sizes from 4 feet long, 1 foot wide, 
and 9 inches deep to 15 inches long, 9 inches wide, and 9 inches 
deep. Prices range from $25 for the largest size to $3.75 for the 
smallest. 
























































CHAPTER XXIV. 


MISCELLANEOUS NOTES. 

1043. Comparison of European and American Methods and 
Prices. —Comparison is frequently made between the methods and 
cost of constructing and maintaining roads and pavements in the 
United States and Europe. In making such comparisons it must 
be remembered (1) that comparisons are of little value unless based 
upon similar conditions; (2) that the cost of materials and labor in 
Europe is generally much less than in America; (3) that the 
methods and cost will vary very much in different parts of the 
same country ; (4) that the cost of constructing and maintaining 
roads and pavements depends upon many diverse elements, due to 
local conditions, customs, and habits, as well as upon the quality of 
the materials, distance of transport, skill of the workmen, charac¬ 
ter of the traffic, climatic conditions, etc. 

Although it is evident that comparisons based upon such vari¬ 
able elements as are enumerated above must be imperfect, never¬ 
theless intelligent observation and comparison of the methods and 
cost of construction and maintenance, both at home and abroad, 
will materially aid in avoiding unnecessary expenditure in experi¬ 
ments, and will promote economy and efficiency. 

Table No. LXXXVIII shows the wages paid in several European 
localities. 


TABLE LXXXVIII. 


Kind of Labor. 

London. 

Berlin. 

Paris. 

England. 

Bel¬ 

gium. 

France. 

Unskilled. 

Foreman . 

So. oo 

$1.00 to $2.00 

$0.48 to $0.70 
$0.83 
$1.50 
$0.71 

$1.60 to $1.80 
$1.50 

$0.80 

$0.90 to $1.20 
$1.20 
$0 80 

$0.90 to $1.10 

$1.60 

$1.56 to $1.75 
$1 00 

$0.06 to 
$0.07* 

$0.58 

$20.00t 

Pavers. 

$1.75 

$0.80 

$1.50 

$2.00 to $2.50 
$1.75 

Sweepers. 

Steam-roller drivers. 

Horse and cart. 

Masons. . 

$0 80 to $0 90 
$0.80 to $1.44 
$1.75 to $2.50 
$1.25 


$1.55 





* Per hour. + Per month. 


680 
























MISCELLANEOUS NOTES. 


681 


In European cities 10 hours constitute a day’s labor. 

Wages in the United States range between the following limits, 
and a day’s work varies from 8 to 10 hours: 

Foremen, $3 to $5. 

Sub-foremen, $1.75 to $2.50. 

Unskilled, $1.25 to $1.75. 

Pavers, $2.50 to $4.50. 

Masons, $3 to $4.50. 

Steam-roller drivers, $3 to $4.50. 

Single horse, cart, and driver, $2.50 to $3.50. 

Double horse, wagon, and driver, $3 to $6. 

Drillers, $2 to $3. 

Sweepers, $1.25 to $2. 

1043a. Statistics of Roads in the United States. —The following 
statistics concerning the weight of load for horses, cost of haulage, 
and length of haul from farms to markets are deduced from the 
investigation conducted by the office of Road Inquiry of the De¬ 
partment of Agriculture. 


AVERAGE WEIGHT OF LOAD FOR TWO HORSES. 


Eastern states. 2216 pounds 

Northern states.2136 

Middle Southern states.1869 

Cotton states. 1397 

Prairie states...2409 

Pacific coast states..2197 

Average for the United States.2002 


AVERAGE COST OF HAULAGE PER TON PER MILE. 


Eastern states. 32 cents 

Northern states.27 “ 

Middle Southern states.31 “ 

Cotton states.25 “ 

Prairie states.22 “ 

Pacific coast states.22 “ 

Average for the United States. 25 “ 


















682 


HIGHWAY CONSTRUCTION". 


AVERAGE LENGTH OF HAUL IN MILES FROM FARMS TO 
MARKET OR SHIPPING POINTS. 


Eastern states. 5.9 

Northern states.6.9 

Middle states. 8.8 

Cotton states.12.6 

Prairie states... 8.8 

Pacific coast states.23.3 

Average for United States. .12.1 


miles 


< ( 

< ( 


< i 


AVERAGE TOTAL COST PER TON FOR THE WHOLE LENGTH OF 


HAUL. 

Eastern states. $1.89 

Northern states. 1.86 

Middle Southern states. 2.72 

Cotton states .. 3.05 

Prairie states. . 1.94 

Pacific coast states. . 5 12 

$ 

Average for the United States. 3.02 


In conquence of the great attention which highway improve¬ 
ment is now receiving and the agitation for the construction of 
light railways connecting the markets and shipping points with 
the farms, accurate and reliable information as to the cost of haul¬ 
age over country roads is in demand, and the above figures, if trust¬ 
worthy, will be received with much satisfaction. 

The accurancy of the figures cannot, however, be tested with¬ 
out a knowledge of the condition of the roads at the time the 
observations were made. If they were earth in a dry and hard con¬ 
dition, the cost seems high ; but if they were earth covered with 
mud and ruts or dry sand they are not excessive. See also Table 
I, page 3. 


















MISCELLANEOUS NOTES. 


683 


1044. Pavements and Horseshoes. —A horse’s hoof shod with a 
heavy iron shoe strikes a blow resembling that struck by a hammer in 
the hand of man, but with considerably more energy. When the shoes 
are furnished with sharp toe-pieces and heel-calks, as in the pre¬ 
vailing form, the combined effect of a cutting chisel and hammer is 
produced. This form of shoe is rendered necessary to obtain foot¬ 
hold on the rough and ill-conditioned pavements generally found 
in use, but on smooth improved pavements it is not required. 
Indeed, its use produces exceedingly destructive effects. Broken- 
stone pavements suffer the most; the surface is excavated and the 
stones displaced. Block pavements also suffer considerably; the 
blocks are chipped and rounded until they assume the form of 
boulders. Wood and asphalt probably suffer the least, unless the 
blows fall successively in the same place. 

The European pavements are not subjected to the destroying 
effect of this form of shoe. There smooth, flat shoes of light weight 
are used, and in many localities the form of the shoe is regulated by 
law. 

Elat shoes and wide tires have a large effect in the conservation 
of pavements, and where improved pavements have been intro¬ 
duced the imposition of a tax would be warranted to hasten their 
use. 

1045. Annual Cost of Structures.— The annual cost of any struc¬ 
ture, or the annual payments required to maintain the structure 
in perpetuity, is composed of three elements: 

(i) Interest on First Cost .—If the structure is built with bor¬ 
rowed money, interest must be paid as a matter of course and charged 
against the structure. If it be not borrowed, but furnished by the 
owner, the case is not essentially different. He takes it from some 
other investment which would pay interest, and is a loser if the new 
structure does not make him the same return. Any structure 
which cannot bear this charge of interest, is a bad investment. But 
if the structure be neither built nor bought, but inherited by its 
present owner, its first cost to him is what he could sell it for; if it 
have no market value, its cost to him is nothing, and he may omit 
the interest charge entirely. 

The general principle is that the cost of any structure is the 
amount of capital which its owner voluntarily keeps in it, and that 
on this amount the interest must be charged against the structure. 



% 


684 


HIGHWAY CONSTRUCTION. 


(2) Annual Repairs .—Under this head is included every expense 
of preserving the property, such as ordinary repairs, watchmen, in¬ 
surance, etc. If by these means the property is maintained in its 
original condition, “ as good as new,” these two elements embrace 
the whole annual cost. But there are many cases in which this is 
not true. In spite of the annual repairs, the structure after a time 
wears out and must be replaced either in whole or in part by a new 
one. If it be a bridge, it has to be rebuilt; if it be a pavement or a 
set of rails, they have to be taken up and replaced by new ones. 
This makes a further payment necessary, viz.: 

(3) Annual Payments to the Renewal Fund .—By this is meant 
the proportion of the sum finally needed to renew the structure 
chargeable to each year. If this fund be raised all at once when it 
is actually needed, the amount chargeable to each year is the total 
sum divided by the number of years in the life of the structure. 
But the amount of each contribution will be made very much 
smaller if it is actually paid each year and each payment improved 
at compound interest after the manner of an ordinary sinking fund 
for the extinction of bonds. This method distributes the burden 
equally over the whole term and makes it much lighter than is pos¬ 
sible in any other way. Taking it for granted that this is the plan 
adopted, the formula to ascertain the value of these elements will 
be as follows: 

Let x — total annual cost, or the annual payments needed to 
maintain the structure in perpetuity; 
a — first cost: 

b = value of old materials when no longer fit for use in the 
structure, and also the value of so much of the struc¬ 
ture as needs no renewal; 
c = cost of annual repairs; 

n = number of years the structure lasts before renewal; 
r = rate of interest on money; 

tn = amount or final value of an annuity of $1.00 com- 


pounded each year for n years, = -I—- ' 


r 


The final cost of renewal = a — h. If the renewals should exceed 
first cost, b will equal the excess, and the total cost of renewal will 
— a -j— b. 




MISCELLANEOUS NOTES. 


C85 


To find the annual payment to the renewal fund, call it p. 
Then will 1 : m ::p : a — b. 

Whence p = --- = {a — h ). 7 — V 

m x ’ (1 -f r) n — 1 

The annual interest charge will be = ar. 

The total annual cost of the structure icill therefore he 


x = ar + c+{a-b). J - 

The factor (1 + r ) n is the amount of one dollar at compound 
interest for n years and is given in Table LXXXIX. 


The value of the whole expression 


r 


(1 + r) n - 1 


is given in Table 


XC. 


As an example of the application of the formula, let the problem 
be to determine the relative economy of a wooden and an iron bridge 
for a given place. Let the length of the bridge be 500 feet, or 4 
spans of 125 feet each, and let the other data be as follows: 

For the wooden bridge 
a — first cost = $25 per foot.— $12,500; 

h = value of iron when the bridge is worn out; = say $2 per 
foot. = $1,000; 

c — cost of annual repairs = $1200; 
n = life of the bridge = 10 years; 
r — 6 per cent = T fo- 

Then will x — $750 $1200 -j - ($12,500X.0<59) — $2822.85. 

For the iron bridge 

a — first cost = $50 per foot. = $25.000.; 
h = value of old materials = say $10 per foot. = $5000; 
c = annual repairs = say $500; 
n — life of bridge = say 60 years; 
r = 6 per cent = T fo- 

Then will x - $1500 + $500 + ($20,000 X .0019) = $2038. 

Showing a saving of $784 per annum by using the iron bridge. 








086 


HIGHWAY CONSTRUCTION". 


TABLE LXXXIX. 

Value of (1 -f- r) n , on the Amount of $1 at Compound Interest fob 

a Term of Years. 

Interest 2 per cent. 


Years. 

Value. 

Years. 

Value. 

Years. 

Value. 

1 

$1,020 

21 

$1,516 

41 

$2,252 

2 

1.040 

22 

1.546 

42 

2.297 

8 

1.061 

23 

1.577 

43 

2.343 

4 

1.082 

24 

1.608 

44 

2.390 

5 

1.104 

25 

1.641 

45 

2.438 

6 

1.126 

26 

1.673 

46 

2.487 

7 

1.149 

27 

1.707 

47 

2,536 

8 

1.172 

28 

1.741 

48 

2.587 

9 

1.195 

29 

1.776 

49 

2.639 

10 

1.219 

30 

1.811 

50 

2 692 

11 

1.243 

31 

1.848 

55 

2.972 

12 

1.268 

32 

1.885 

60 

3.281 

13 

1.294 

33 

1.922' 

65 

3.623 

14 

1.319 

' 34 

1.961 

70 

4.000 

15 

1.346 

35 

2.000 

75 

4.416 

16 

1.373 

36 

2.040 

80 

4.875 

17 

1.400 

37 

2.081 

85 

5.383 

18 

1.428 

38 

2.122 

90 

5.943 

19 

1.457 

39 

'2.165 

95 

6.562 

20 

1.486 

40 

2.208 

100 

7.245 


Interest 3 per cent. 


1 

$1,030 

21 

$1,860 

41 

$3 360 

2 

1.061 

22 

1.916 

42 

3.461 

3 

1.093 

23 

1.974 

43 

3.565 

4 

1.126 

24 

2.033 

44 

8 fiTI 

5 

1 159 

25 

2.094 

45 

3.782 

6 

1.194 

26 

2.157 

46 

3.895 

7 

1.230 

27 

2.221 

47 

4.012 

8 

1.267 

28 

2.288 

48 

4.132 

9 

1.305 

29 

2.357 

49 

4.256 

10 

1.344 

30 

2.427 

50 

4 384 

11 

12 

1.384 

1.426 

31 

32 

2.500 

2.575 

55 

60 

5.082 

5.892 

13 

1.469 

33 

2.652 

65 

6.830 

14 

•1.513 

34 

2.732 

70 

7.918 

15 

1.558 

35 

2.814 

75 

9.179 

16 

1.605 

36 

2.898 

80 

10.641 

17 

1.653 

37 

2.985 

85 

12.336 

18 

1.702 

38 

3.075 

90 

14 300 

19 

1.754 

39 

3.167 

95 

16.578 

20 

1.806 

40 

3.262 

100 

19.219 





































MISCELLANEOUS NOTES 


687 


Y alije of (1 -J- r) n . ( Continued .) 
Interest 3i per cent. 


Years. 

Value. 

Years. 

Value. 

Years. 

Value. 

1 

$1 035 

21 

$2,059 

41 

$4,098 

2 

1.071 

22 

2.132 

42 

4.241 

3 

1.109 

23 

2.206 

43 

4.390 

4 

1.148 

24 

2.283 

44 . 

4.543 

5 

1.188 

25 

2.363 

45 

4.702 

6 

1.229 

26 

2.446 

46 

4.867 

7 

1.272 

27 

2.532 

47 

5.037 

8 

1.317 

28 

2.620 

48 

5.214 

9 

1.363 

29 

2.712 

49 

5.396 

10 

1.411 

30 

2.807 

50 

5.585 

11 

1.460 

31 

2.905 

55 

6.633 

12 

1.511 

32 

3.007 

60 

7.878 

13 

1.564 

33 

3.112 

65 

9.357 

14 

1.619 

34 

3.221 

70 

11.113 

15' 

1.675 

35 

3.334 

■75 

13.199 

16 

1.734 

36 

3.450 

80 

15.676 

17 

1.795 

37 

3.571 

85 

18.618 

18 

1.857 

38 

3.696 

90 

22.112 

19 

1.923 

39 

3.825 

95 

26.262 

20 

1.990 

40 

3.959 

100 

31.191 


Interest 4 per cent. 


1 

$1,040 

21 

$2,279 

41 

$4,993 

2 

1.082 

22 

2.370 

42 

5.193 

3 

1.125 

23 

2.465 

43 

5.400 

4 

1.170 

24 

2.563 

44 

5.617 

5 

1.217 

25 

2.666 

45 

5.841 

6 

1.265 

26 

2.772 

46 

6.075 

7 

1.316 

27 

2.883 

47 

6.318 

8 

1.369 

28 

2.999 

48 

6.571 

9 

1.423 

29 

3.119 

49 

6.833 

10 

1.480 

30 

3.243 

50 

7.107 

11 

1.539 

31 

3.373 

55 

8.646 

12 

1.601 

32 

3.508 

60 

10.520 

13 

1.665 

33 

3.648 

65 

12.799 

14 

1.732 

34 

3.794 

70 

15.572 

15 

1.801 

35 

3.946 

75 

18.945 

16 

1.873 

36 

4.104 

80 

23.050 

17 

1.948 

37 

4.268 

85 

28.044 

18 

2.026 

38 

4.439 

90 

34.119 

19 

2.107 

39 

4.616 

95 

41.511 

20 

2.191 

40 

4.801 

100 

50.505 









































688 


HIGHWAY CONSTRUCTION. 


Value of (l-J-r) n . ( Continued .) 
Interest 4 h per cent. 


Years. 

Value. 

Years. 

Value. 

Years. 

Value. 

1 

$1,045 

21 

$2,520 

41 

$6,078 

2 

1.092 

22 

2.634 

42 

6.352 

3 

1.141 

23 

2.752 

43 

6.637 

4 

1.193 

24 

2.876 

44 

6.936 

5 

1.246 

25 

3.005 

45 

7.248 

6 

1.302 

26 

3.141 

46 

7.574 

7 

1.361 

27 

3.282 

47 

7.915 

8 

1.422 

28 

3.430 

48 

8.271 

9 

1.486 

29 

3.584 

49 

8.644 

10 

1.553 

30 

3.745 

50 

9.033 

11 

1.623 

31 

3.914 

55 

11.256 

12 

1.696 

32 

4.090 

60 

14.027 

13 

1.772 

33 

4.274 

65 

17.481 

14 

1.852 

34 

4.466 

70 

21.784 

15 

1.935 

35 

4.667 

75 

27.147 

16 

2.022 

36 

4.877 

80 

33.830 

17 

2.113 

37 

5.097 

85 

42.158 

18 

2.208 

38 

5.326 

90 

52.537 

19 

2.308 

39 

5.566 

95 

65.471 

20 

2.412 

40 

5.816 

100 

81.589 


Interest 5 per cent. 


1 

$1,050 

21 

$2,786 

41 

$7,392 

2 

1.103 

22 

2.925 

42 

7.762 

3 

1.158 

23 

3.072 

43 

8.150 

4 

1.216 

24 

3.225 

44 

8.557 

5 

1.276 

25 

3.386 

45 

8.985 

6 

1.340 

26 

3.556 

46 

9 434 

7 

1.407 

27 

3.733 

47 

9.906 

8 

1.477 

28 

3.920 

48 

10.401 

9 

1.551 

29 

4.116 

49 

10.921 

10 

1.629 

30 

4.322 

50 

11.467 

11 

1.710 

31 

4.538 

55 

14.636 

12 

1.796 

32 

4.765 

60 

18.679 

13 

1.886 

33 

5.003 

65 

23.840 

14 

1.980 

34 

5.253 

70 

30.426 

15 

2.079 

35 

5.516 

75 

38.833 

16 

2.183 

36 

5.792 

80 

49.561 

17 

2.292 

37 

6.081 

85 

63.254 

18 

2.407 

38 

6.385 

90 

80.730 

19 

2 527 

39 

6.705 

95 

103.035 

20 

2.653 

40 

7.040 

100 

131.501 







































MISCELLANEOUS NOTES. 


689 


Value of (1 -j- r) n . ( Continued.) 


Interest 6 per cent. 


Years. 

Value. 

Years. 

Value. 

Years. 

Value. 

1 

11.060 

21 

$3,400 

41 

$10,903 

2 

1.124 

22 

3.604 

42 

11.557 

3 

1.191 

23 

3.820 

43 

12.250 

4 

1.262 

24 

4.049 

44 

12.985 

5 

1.338 

25 

4.292 

45 

13.765 

6 

1.419 

26 

4.549 

46 

14 590 

7 

1.504 

27 

4.822 

47 

15.466 

8 

1.594 

28 

5.112 

48 

16.394 

9 

1.689 

29 

5.418 

49 

17.378 

10 

1.791 

30 

5.743 

50 

18.420 

11 

1.898 

31 

6.088 

55 

24.650 

12 

2.012 

32 

6.453 

60 

32.988 

13 

2.133 

33 

6.841 

65 

44.145 

14 

2.261 

34 

7.251 

70 

59.076 

15 

2.397 

35 

7.686 

75 

79 057 

16 

2.540 

36 

8.147 

80 

105.796 

17 

2.693 

37 

8.636 

85 

141.579 

18 

2.854 

38 

9.154 

90 

189.465 

19 

3.026 

39 

9.704 

95 

253.546 

20 

3.207 

40 

10.286 

100 

339.302 


TABLE XC. 

V 

Value of —-, on the Sinking Fund that with Compound Inter* 

(1 + r) n — 1 

EST WILL AMOUNT TO ONE DOLLAR AT THE END OF A TERM OF YEARS. 


Interest 3 per cent. 


Years. 

Value. 

Years. 

Value. 

Years. 

Value. 

1 

$1.0000 

21 

$0.0349 

41 

$0.0127 

2 

.4926 

22 

.0327 

42 

.0122 

3 

.3235 

23 

.0308 

43 

.0117 

4 

.2390 

24 

.0290 

44 

.0112 

5 

.1884 

25 

.0274 

45 

.0108 

6 

.1546 

26 

.0259 

46 

.0104 

7 

.1305 

27 

.0246 

47 

.0100 

8 

.1125 

28 

.0233 

48 

.0096 

9 

.0984 

29 

.0221 

49 

.0092 

10 

.0872 

30- 

.0210 

50 

.0089 

11 

.0781 

31 

.0200 

55 

.0073 

12 

.0705 

32 

.0190 

60 

.0061 

13 

.0640 

33 

.0182 

65 

.0051 

14 

.0585 

34 

.0173 

70 

.0043 

15 

.0538 

35 

.0165 

75 

.0037 

16 

.0496 

36 

.0158 

80 

.0031 

17 

.0460 

37 

.0151 

85 

.0026 

18 

.0427 

38 

.0145 

90 

.0023 

19 

.0398 

39 

.0138 

95 

.0019 

20 

.0372 

40 

.0133 

100 

.0016 












































690 


HIGHWAY CONSTRUCTION. 


Value of 


r 

(1 _|_ r )n _ i* 


( Continued.) 


Interest 34 per cent. 


Years. • 

Value. 

Years. 

Value. 

Years. 

Value. 

1 

$1.0000 

21 

$0.0330 

41 

$0.0113 

2 

.4914 

22 

.0309 

42 

.0108 

Q 

O 

.3219 

23 

.0290 

43 

.0103 

4 

.2373 

24 

.0273 

44 

.0099 

5 

.1865 

25 

.0257 

45 

.0095 

6 

.1527 

26 

.0242 

46 

.0091 

7 

.1285 

27 

.0229 

47 

.0087 

8 

.1105 

28 

.0216 

48 

.0083 

9 

.0964 

29 

.0204 

49 

.0080 

10 

.0852 

30 

.0194 

50 

.0076 

11 

.0761 

31 

.0184 

55 

.0062 

12 

.0685 

32 

.0174 

60 

.0051 

13 

.0621 

33 

.0166 

65 

.0042 

14 

.0566 

34 

.0158 

70 

.0035 

15 

.0518 

35 

.0150 

75 

.0029 

16 

.0477 

36 

.0143 

80 

.0024 

17 

.0440 

37 

.0136 

85 

.0020 

18 

.0408 

38 

.0130 

90 

.0017 

19 

.0379 

39 

.0124 

95 

.0014 

20 

.0354 

40 

.0118 

100 

.0012 


Interest 4 per cent. 


1 

$1.0000 

21 

$0.0313 

41 

$0.0100 

2 

.4902 

22 

.0292 

42 

.0095 

3 

.3204 

23 

.0273 

43 

.0091 

4 

.2255 

24 

.0256 

44 

.0087 

5 

.1846 

25 

.0240 

45 

.0083 

6 

.1508 

26 

.0226 

46 

.0079 

7 

.1266 

27 

.0212 

47 

.0075 

8 

.1085 

28 

.0200 

48 

.0072 

9 

.0945 

29 

.0189 

49 

.0069 

10 

.0833 

30 

.0178 

50 

0066 

11 

.0742 

31 

.0169 

55 

.0052 

12 

.0666 

32 

.0160 

60 

.0042 

13 

.0604 

33 

.0151 

65 

.0034 

14 

.0547 

34 

.0143 

70 

.0027 

15 

.0499 

35 

.0136 

75 

.0022 

16 

.0458 

86 

.0129 

80 

.0018 

17 

.0422 

37 

.0122 

85 

.0015 

18 

.0390 

38 

.0116 

90 

.0012 

19 

.0361 

39 

.0111 

95 

.0010 

20 

.0336 

40 

.0105 

100 

.0008 




































MISCELLANEOUS NOTES. 


691 


Value of — ^ ( Continued.) 

Interest 5 per cent. 


Years. 

Value. 

Years. 

Value. 

Years. 

Value. 

1 

$1.0000 

21 

$0 0280 

41 

$0.0078 

o 

& 

.4878 

22 

.0260 

42 

.0074 

3 

.3172 

23 

0241 

43 

.0070 

4 

.2320 

24 

.0225 

44 

.0066 

5 

.1810 

25 

.0210 

45 

.0063 

6 

.1470 

26 

.0196 

46 

.0059 

7 

.1228 

27 

.0183 

47 

.0056 

8 

.1047 

28 

.0171 

48 

0053 

9 

.0907 

29 

.0160 

49 

.0050 

10 

.0795 

30 

.0151 

50 • 

.0048 

11 

.0704 

31 

.0141 

55 

.0037 

12 

.0628 

32 

.0133 

60 

.0028 

13 

.0565 

33 

.0125 

65 

.0022 

14 

.0510 

34 

.0118 

70 

.0017 

15 

.0463 

35 

.0111 

75 

.0013 

16 

.0423 

36 

.0104 

80 

.0010 

17 

.0387 

37 

.0098 

85 

.0008 

18 

.0355 

38 

.0093 

90 

.0006 

19 

.0327 

39 

.0088 

95 

.0005 

20 

.0302 

40 

.0083 

100 

.0004 


Interest 6 per cent. 


1 

$1.0000 

21 

$0.0250 

41 

$0.0061 

2 

.4 s 54 

22 

.0230 

42 

.0057 

3 

.3141 

23 

.0213 

43 

.0053 

4 

.2286 

24 

.0197 

44 

.0050 

5 

.1774 

25 

.0182 

45 

.0047 

6 

.1434 

26 

.0169 

46 

.0044 

7 

.1191 

27 

.0157 

47 

.0041 

8 

.1010 

28 

.0146 

48 

.0039 

9 

.0870 

29 

.0136 

49 

.0037 

10 

.0759 

30 

.0126 

50 

.0034 

11 

.0668 

31 

.0118 

55 

.0025 

12 

.0593 

32 

.0110 

60 

.0019 

13 

.0530 

33 

.0103 

65 

.0014 

14 

15 

.0476 

34 

.0096 

70 

.0010 

.0430 

35 

.0090 

75 

.0008 

16 

.0390 

36 

.0084 

80 

.0006 

17 

.0354 

37 

.0079 

85 

.0004 

18 

.0324 

38 

.0074 

90 

.0003 

19 

.0296 

39 

.0069 

95 

.0002 

20 

.0272 

40 

.0065 

100 

.0002 











































APPENDIX. 


i. 

NAMING AND NUMBERING COUNTRY ROADS AND HOUSES. 

1. The naming of country roads and the numbering of country 
houses has not generally received that recognition which its impor¬ 
tance demands ; consequently commercial and social intercourse in 
rural sections is rendered extremely inconvenient. Ihe indiffer¬ 
ence of rural communities on this subject has been due to several 
causes, but mainly to the want of a system which was applicable to 
all localities, and which should, without serious complication, be 
sufficiently elastic to cover the changes wrought by improvement. 
Such a system is now available. It is known as the “ Ten-block 
Method ” devised by Mr. A. L. Bancroft, and now in successful use 
in Contra Costa County, Cal. 

2. The Ten-block System— In this system the roads are first 
named in as long lengths as possible (names of towns or living 
residents are not used,—some landscape feature or historical asso¬ 
ciation suggesting the name) and then carefully measured. The 
point from which the measurements of all roads within the county 
are commenced is the centre of the roadway directly in front of the 
main entrance to the county court-house; each mile is divided into 
10 blocks of 528 feet, and each block is numbered, the even num¬ 
bers being placed on the right-hand side and the odd ones on the 
left-hand side going from the court-house; the block numbers are 
'conspicuously marked on the fences or on posts specially placed for 
the purpose; a line indicating the division of the block is placed 
between the numbers thus, 52 | 50; the end of each mile is indi¬ 
cated by an X painted inside a circle, the half-mile is marked by a 
V in a semicircle; the houses in each block have the same numbers 
as the block on which they stand, but are distinguished by a letter 
of the alphabet affixed thereto, as 3A, 3B, to 3Z; thus when new 

692 



APPENDIX. 


693 


houses are built in the block they can have numbers assigned to 
them without interfering with those already numbered; the num¬ 
ber of roads entering or intersecting a given road makes no differ¬ 
ence with the length or number of the block; in passing through 
villages or towns the names and numbers already in use are left 
unchanged, but outside the town limits the ten-block system is 
resumed, the first house having a number depending upon its dis¬ 
tance from the court-house. In this way, although a road passes 
through a dozen towns, the numbers on each side of the town 
indicate the true position of the house and its distance from the 
commencement of the road. The distance from the court-house or 
between any two given houses is quickly ascertained by dividing 
half the even numbers by 10; for instances, if a house is numbered 


506 253 

506, its distance from the county court-house is —- = —- = 25 T 3 ¥ 


miles, or the distance of the same house beyond another house 

, , . , , 506 315 253 - 157 _ 

numbered 315 is equal to —- - =-^- = 9 T % miles, 


2 


2 


and on the opposite side of the road. 

3. The data necessary to put this system in operation are con¬ 
tained in the following ordinance of the Board of Supervisors of the 
county of Contra Costa, Cal.: 


An ordinance of the Board of Supervisors of the county of Contra 
Costa, State of California, naming the severed public highways 
of the county and authorizing the use of certain other names 
and designations for private or local roads in use in said 
county; also providing for the erection and due preservation 
of suitable guide-boards at all road crossings and intersec¬ 
tions, and at other necessary or suitable points upon such 
roads as have been properly measured or divided into blocks, 
according to the “ Ten-block System” also providing for the 
affixing and maintaining by residents of house or farm-entrance 
numbers, based thereon, for all country residences upon such 
measured roads; also providing for an official road map of the 
county, and other records. 

The Board of Supervisors of the County of Contra Costa do 
ordain as follows : 

Section 1. All public highways which have been duly accepted 








C94 


APPENDIX. 


by the county shall hereafter be known and designated by the 
names prescribed in this ordinance, according to the designation 
and descriptions laid down in Section 29. 

Sec. 2. All private or local roads designated in Sec. 29 of this 
ordinance shall in all official reference thereto be hereafter known 
by the names herein prescribed, and the public use and recognition 
of such designation is hereby recommended. 

Sec. 3. Whenever the owner or owners of any strip or strips of 
land within the county shall represent to the Board of Supervisors 
their purpose and wish to devote the same to use as a public or 
private road, or as a right of way for access to any dwelling, and 
shall offer or accept a name for the same, approved by the road 
committee, to be appointed or confirmed by the Board of Super¬ 
visors, and shall comply with the provisions of the law respecting 
roads, such road name shall, when approved by the Board of 
Supervisors, be thereafter used in all official reference to the same, 
and its public use shall be recommended. Such road shall then be 
listed in the road list and given a designating number and letter 
immediately following the number of the road to which it is adja¬ 
cent or tributary, until such time as the Board of Supervisors shall 
revise the list and renumber the roads. And such road shall 
thereafter come under the provisions of this ordinance the same as 
the roads enumerated. 

Sec. 4. The streets of all unincorporated towns or villages in 
the county may come within the provisions of this ordinance and 
be named. When numbered, the numbers to be according to the 
town method of 100 numbers to the actual block or square. 

Sec. 5. The authorities of the village, town, or city incorpora¬ 
tions in the county are recommended and urged to name the 
streets within their corporate limits, and to cause the houses 
thereon to be numbered ; also, to make use of one of the following 
designations only for the roadways within such incorporation, viz. : 
Alley, Avenue, Boulevard, Court, Park, Place, Plaza, Promenade, 
Row, Square, Street, Terrace. 

Sec. 6. Road measuring and numbering, as contemplated by this 
ordinance, are hereby defined and described as follows : All roads 
shall be measured along the surface line of the same, as near to 
the middle of the roadway as practicable, and laid off in imaginary 
blocks one tenth of a mile, or 528 feet frontage each, according to 



APPENDIX. 


695 


the “ Ten-block System of Numbering Country Houses.” A line 
to indicate the division between these blocks, with the block num¬ 
ber on either side of the same, shall be marked or painted upon the 
fence where practicable, and where it exists in a fair state of pres¬ 
ervation, or upon any other permanent object on one or both sides 
of the road. The odd numbers shall be applied to the blocks on 
the left-hand side of the road, and the even numbers to the right- 
hand side. The block numbers shall be in figures not less than 
two inches nor more than two and one half inches in height where 
the fence board or other object will admit of this size, and so 
plainly painted as to be easily read from the centre of the road. 
The mile distances shall be distinguished in some suitable manner, 
as by a full circle, and the half-mile by a half circle or other suit¬ 
able device. 

Sec. 7. The initial point of measuring for roads leading from the 
county seat shall be the centre of the street immediately in front 
of the main entrance to the court-house at Martinez. Other roads 
shall be measured at the end nearest the county seat, and branch 
roads the same, or from the main road to which they are tributary. 

Sec. 8. Note shall also be taken and a record kept of the block 
within which is located, and the number of feet in or within the 
block (i. e., the distance from the commencement of the block), of 
all bridges, large culverts, important permanent springs, drinking 
troughs, public monuments, summits, road crossings and intersec¬ 
tions and objects of special prominence, and the correct block num¬ 
ber be marked thereon, or near thereto, where practicable. 

Sec. 9. Note shall also be made and a record be kept of the 
number of the block within which is located, and the number of feet 
in or within the block, of each and every house entrance or gate¬ 
way, lane, or road leading from the highway to any residence upon 
the roads, or to which access is had by way of the road, with the 
name or names of the owner or occupant, when practicable to pro¬ 
cure them; also, to the entrance to all school-houses, churches, and 
public buildings. 

Sec. 10. The measurement of all roads which pass through or 
enter the corporate limits of cities or towns shall be continuous, 
regardless of such boundaries ; but the block and country-house 
numbers may be omitted within such corporations. 

Sec, 11. In the measurement of the roads of the county re- 




696 


APPENDIX. 


quired by this ordinance a record shall be made and preserved 
of the general course of bearings by the compass of all roads at 
road crossings or intersections; also, the general course of all private 
or local roads at their point of departure from the main road; and 
it shall be the duty of the county surveyor to prepare and place on 
file, in the office of the clerk of the county, a complete road map 
of the county, with the names of all roads, and, whenever the same 
are measured, the block numbers at their commencement at all 
roads, crossings, and at all crossings and connections of all roads, 
and at their endings, together with the boundaries of the several 
road districts in the county. 

Sec. 12. The measurement of the roads of the county may in¬ 
clude the record of the accurate reading by barometer of the alti¬ 
tudes or elevations above the sea-level of the commencement and 
ending of all roads, all plains, valleys, the foot and summit of hills 
and the slopes of mountains, at suitable distances. The records of 
such altitudes, if taken, to be placed over the block number nearest 
the point of observation, or otherwise suitably posted, to show the 
range of important elevations traversed. 

Sec. 13. Whenever one or more residents or owners, upon any 
road enumerated in section 29, or hereafter designated and 
described, as required by this ordinance, or other person, shall 
furnish the Board of Supervisors satisfactory evidence that the 
provisions of this ordinance, respecting road measuring and number¬ 
ing, have been faithfully complied with upon any road touching the 
county seat, or upon any road connecting with any other road 
which has been previously measured and blocked off; and when¬ 
ever such residents shall file with the county clerk the record 
required in sections 8, 9, and 11; and whenever such resident, resi¬ 
dents, or other persons shall have affixed block numbers at the be¬ 
ginning and ending of such roads, and at each mile and half-mile 
division thereof, where practicable or oftener,—then, and in that 
case, it shall be the duty of the Board of Supervisors to erect upon 
such road, or roads, guide-boards, as hereinafter prescribed. 

Sec. 14. Whenever any such road is so measured and block num¬ 
bers designated thereon, thenceforth and thereafter the several 
requirements of this ordinance as to the maintenance of house 
numbers, the protection and preservation of guide-boards, etc.. 



APPENDIX. 


697 


shall become applicable and in force along and upon such road, or 
roads, and the penalties herein prescribed shall be duly enforced. 

Sec. 15. The guide-boards, when ordered upon any road, shall 
be erected and permanently maintained at the following-named 
points, and at such places as the Board of Supervisors may here¬ 
after prescribe: At or near the commencement of all roads or 
branch roads, at all road crossings or intersections, at all ferry 
landings, at all railroad stations, and at all crossings of the county 
boundary. They shall be so placed on the principal roads as to 
face the traveller when moving from the county seat. 

Sec. 16. Such guide-boards shall be of iron, not less than No. 16 
in thickness, galvanized and painted. They shall be at right angles 
to fit the post, and with two arms or boards for the lettering. The 
outer edges shall be bent back from the face one half inch in 
width, the lower portion being cut away the width of the post, and 
the upper lip to rest on top of the post, to which the board must 
be securely atttached by a sufficient number of screws. The posts 




GRANVILLE WAY 

From 2/1 C.C.H/QHIYAYto86 Y/sta IgnaciaSBNos 

0 

o 

o 

o 

0 


Concord 

Clayton 

Lafayette 

Oakland 


10.5 M 

16.2 M 

5.6 M 

12.9 M 
Euv.96ft 


mm 




|M0.1_A r ^ 6e: M^T OfJW0^DUl6 Otf^GlifoV B0\RD$ 


shall be of sound redwood, 6x6 inches, and twelve feet long, to be 
set three feet in the ground, with cross-pieces nailed to the post, in 
light soils. The top and the portion below the ground to be in or 
painted with coal-tar, or some other wood preservative, the por¬ 
tion above the ground to be painted with two coats of good metal¬ 
lic or other suitable paint. The exposed surface of the boards 























098 


APPENDIX. 


shall be 15 x 24 inches in size, each, except at the entrance to local 
roads, which may have bnt a single projecting arm 6x15 inches in 
size and affixed to a 4x4 inch post; in all other particulars to be 
of similar construction to the larger size; the wording and lettering 
to conform to the general plan indicated by the design accompanying 
this ordinance, and made a part thereof. All of the lettering upon 
the guide-boards, except the second line, which is in letters smaller 
than the others, and a section of eighteen inches of the two faces 
of the guide-post directly under the guide-board, shall be painted 
with luminous paint. 

Sec. 17. Upon all guide-posts the following notice shall be con¬ 
spicuously painted or stencilled: 

A Penalty for Defacing or Posting. 

Sec. 18. Whenever the provisions of section 13 have been com¬ 
plied with as to road or roads, and guide-boards have been erected, 
the supervisors shall also cause a printed notice to be served upon 
the occupants of every residence upon such road or roads outside 
the limits of incorporated towns, left at such residence, or, where 
the residence is distant a mile or more from the public or named 
roads, mailed to their address, accompanied by a copy of this 
ordinance or abstract thereof. Such notice shall also be delivered 
or mailed to one of the officers of each school district and church of 
which the building is located upon said measured road. These 
notices shall have a blank form, to be properly filled with the exact 
location and correct number of the entrance to the house, ’with 
instructions as to the house number to be posted and maintained. 

Sec. 19. Every householder upon such measured road, residing 
outside the limits of incorporated towns, shall, within thirty days 
after the service of the notice required in section 18, post, and 
thereafter permanently maintain in legible condition, upon the 
road or at the entrance or right of way from the road, the correct 
house number of his residence as given in said notice. It shall be 
placed in such a conspicuous position as to be easily seen and read 
from the centre or opposite side of the road. The figures shall be 
well proportioned, and of a size not less than three inches in height, 
nor more than four inches, except in town or village settlements, 
where the numbers may be one inch less in height, and may be 
maintained upon the doorway or at the gate. The numbers must 



APPENDIX. 


699 


be neatly made, and in the style and manner that a professional 
sign-writer would use. 

Sec. 20. Any owner or occupant of any dwelling in the county 
which is reached by a private road or right of way is hereby per¬ 
mitted to post and maintain his house number upon the public 
highway at the entrance to such private road or right of way, or 
upon such private road or right of way, and he or she may place 
therewith his or her own name and business, provided such sign is 
made in a neat and tasteful manner, and conforms to the provisions 
of this ordinance. 

Sec. 21. Whenever the occupant of any dwelling upon a 
measured and numbered road shall fail for the term of thirty 
days to maintain the proper house number at the entrance thereto, 
and having been notified by the road officer to comply with the 
law shall fail to do so, he shall be deemed guilty of a misdemeanor. 

Sec. 22. Whenever any house upon a measured and numbered 
road now vacant shall be occupied, or any new dwelling-house shall 
be erected upon such road, it shall be the duty of the occupant 
within thirty days to properly post and thereafter permanently 
maintain, at the entrance thereto, the correct house number of the 
same as provided in this ordinance, and such residence shall there¬ 
after come under the provisions of this ordinance the same as 
dwelling now occupied. 

Sec. 23. There shall be prepared for county use a book of 
records for the roads of the county, in which shall appear, arranged 
in proper order, under the name of each road, an index of all 
ordinances or other official action relating to that road, making 
such road record an official history of all the roads of the county. 

Sec. 24. A copy of all the field notes of the survey measure¬ 
ments, elevations, and other records, with the block and house 
numbers as provided for, shall be carefully preserved in the office 
of the county clerk, and open to the inspection of citizens as are 
other county records. 

Sec. 25. The execution of the work required by this ordinance 
shall be subject to the inspection and be made to conform to the 
requirements of a road committee to serve without pay, and to con¬ 
sist of three members, one to be appointed by the Board of Super¬ 
visors, one to be named by the road-naming committee who have 
prepared this plan, and the third to be chosen by the two thus 




700 


APPENDIX. 


appointed, and all to be confirmed by the Board of Supervisors; 
and any work of measurement, erecting guide-boards, or affixing 
numbers, shall not be held to be complete until approved by a 
majority of this committee. 

Sec. 26. It shall be the duty of the road officials to thoroughly 
inspect the roads within their respective districts and to make reports 
to the Board of Supervisors at least as often as at the close of each 
six months of their terms of office, as to the condition of such 
roads, and any failure to comply with the provision of this ordi¬ 
nance. They shall also see that guide-boards are preserved in a 
legible condition and house numbers properly maintained, notifying 
residents of any neglect in this respect. It shall be their duty to 
report any person charged with violating the provisions of this ordi- 



NO. 2. GUIDE BOARD at right ANGLES TO KQ.l. 

nance, and to enter complaint against them in such case; they shall 
also have full authority to arrest any person or persons found 
defacing or removing block or house numbers, or mutilating any 
guide-board, or posting any notice upon the post or boards, or in 
any way violating the provisions of this ordinance. 

Sec. 27. If any person or persons shall mutilate, deface, destroy, 
or remove any guide-board or guide-post, any block or house num¬ 
ber, any name, sign, or advertisement which may be lawfully posted 
at or upon the entrance to the residence or dwelling of any person 
to whom such notice belongs, whether such entrance be public or 
private or through right of way, or shall mar, deface, or injure, by 
shooting, stoning, or otherwise, any guide post or board, or shall 





















I 


APPENDIX. 701 

fasten, or paint, or stencil any notice or advertisement to such posts 
or boards, save such as are required by this ordinance, the person 
or persons so offending shall be deemed guilty of misdemeanor, 
punishable, upon due conviction, by a fine of $50, one half of 
which shall go to the informer, or by imprisonment, or both. 

Sec. 28. The roads of the county, as enumerated in section 29, 
are listed according to the following rule : Commence on the 
east side of a line extending due north from the county seat and 
work around in a circle to the east, southwest, and back again to 
the north, always facing outward and working from the county seat 
outward, and always from the left to the right. List first those 
roads touching the county seat ; next the first left-hand branch 
roads, and any left-hand branches of these. Continue with the 
right-hand branches, follow with the remaining trunk roads and 
their branches, left-hand branches first, right-hand branches 
next ; omitting nothing on the left until the entire circuit has 
been made and the roads of the county are all listed. Under this 
rule the roads leading from Martinez, five of them are first listed ; 
then the first of the five which have branches, No. 2, and then con¬ 
tinued in the order explained above. 

Sec. 29. The following are the names of several public high¬ 
ways and private or local roads of the county, respectively hereby 
authorized and established. [List of 130 roads, among which are : 

Alpha Way, from Martinez to Bull’s Head ; Contra Costa 
Highway, from Martinez to County line via Pacheco, Walnut 
Creek, and San Ramon Valley ; Alhambra Way, from Martinez to 
Pinole ; Granville Way, from Contra Costa Highway, near Wal¬ 
nut Creek, to Vista Ignacio, Franklin Road ; Teal Local ; Tule 
Road, Pecheco Exit, Vine Hill Way ; Locust Way, Plover Connex; 
Willow Pass Road ; Flunaveg (River Road), Black Diamond 
Way ; Empire Road ; Paso Corto ; Camino Diablo, Carbon Way ; 
Arbor Connex ; Lone Tree. Road, Almond Way ; Summer Road, 
Dry Creek Local ; Zigzag AYay, Sunol Local ; Concord Lateral ; 
Pomona Road; Ferndale Local ; Golden Gate Way; Vaca Cres¬ 
cent ; Verdel Circuit; Acorn Local, Highland Drive ; and Forest 

Road.] 

Sec. 30. This ordinance shall take effect and be in force on the 
16th day after its passage. 

Passed March 8, 1892. 




APPENDIX. 


ii. 

METHODS OF ASSESSING THE COST OF STREET PAYING. 

The following summary shows the different methods employed 
for assessing the cost of street paying: 

1. The whole cost borne by the city at large. 

2. The whole cost borne by the abutting property. 

3. The cost divided equally between the abutting property and 
the city. 

4. The cost divided in the proportion of two thirds on the abut¬ 
ting property and one third on the city. 

5. The abutting property pays for its frontage and the city for 
the intersections. 

6. The abutting property pays a proportion according to the 
benefits received, and the city pays the balance. 

In all cases where the property is assessed the assessment is upon 
the frontage, the location or value of the property not governing 
the amount. 

In cases where the cost is borne by the city at large it is paid 
either from the general tax or by the emission of bonds or improve¬ 
ment certificates. 

The street-railway companies are either assessed directly for the 
area occupied by them, or are required to do the paving and main¬ 
tain and keep in repair the space between their rails and from one 
and one half to two feet outside the rails. 

The following table shows the method employed in some of the 
principal cities of the United States. 


702 



APPENDIX. 


703 


TABLE SHOWING THE METHOD OF ASSESSING THE GOST OF 
STREET PAYING IN DIFFERENT CITIES. 


City 


Albany, N. Y- 

Allegheny, Pa... 

Baltimore, Md- 

Brooklyn, N. Y... 


Buffalo, N. Y_ 

Cincinnati, O.... 

Cleveland, O. 

Chicago, Ill. 

Denver, Col. 

Detroit, Mich ... 


Hartford, Ct. 

Indianapolis, Ind. 
Jersey City, N. J. 


Milwaukee, Wis.. 
Minneapolis, Min. 
Nashville, Tenn.. 
New Haven, Ct... 
Newark, N. J. . . 
New York, N. Y. 

Omaha, Neb. 

Oswego, N. Y- 

Philadelphia, Pa.. 
Pittsburg, Pa ... . 
Rochester, N. Y.. 
St. Louis, Mo.... 
St. Paul, Minn ; .. 
Syracuse, N. Y... 
Troy, N. Y. 


Utica, N. Y 


Abutting Property 
Pays 


entire cost 
frontage only 
frontage only 
amount of bene¬ 
fit it receives 

entire cost 
98^ of cost 
ff of cost 
entire cost 

entire cost 
frontage 


two thirds 
entire cost 
entire cost 


frontage 

frontage 

two thirds 
frontage 
entire cost 

frontage 
two thirds 
frontage 
entire cost 
entire cost 
entire cost 
entire cost 
entire cost 
entire cost 


two thirds 


City at Large 
Pays 


intersections 

intersections 


2 % and intersections 
and intersections 


intersections 


one third 


intersections 
intersections 
entire cost 
one third 
intersections 


intersections 
one third 
intersections 


in streets over 40 
feet wide city pays 
one half 
one third 


Remarks. 


In some cases of re¬ 
paving city pays 
one half. 


In five yearly in¬ 
stalments. 

Assessments are 
payable within 
four years. 


Except in cases of 
extra ordinarily 
heavy work. 


Paid in instalments 
from 5 to 10 years. 

































INDEX. 


A 

ARTICLE PAGE 

63. Abrasion of granite. 26 

63. limestone. 26 

63. paving-brick. 26 

63. wood. 26 

, 61. tests of. . 25 

64. Absorptive power of bricks (Table Y).... .. 2i 

cement (Table XLIV). 262 

granite (Table V). 26 

limestones (Table V).. 26 

marbles (Table V). 26 

64. materials, effect of. 26 

64. mortar (Table Y). 26 

64-119. paving-bricks (Table Y and Table XXI).26, 67 

sandstones (Table V). 26 

64. stones, etc. (Table V). 26 

64. wood (Table Y and Table XXIII).26,74 

706. Abutments for pipe-culverts. 384 

714. thickness of (Table LXXYI).392-394 

22. Accidents to horses. 10 

753. Accommodation summits . 384 

862. Accounts. 501 

617. Acres, number of, required per mile, for different widths of roads 

(Table LXIII). 333 

59-410. Action of the weather...24, 220 

482. Activit}' of cement. 260 

486. tests for.. 262 

9. Adaptability of pavements. 4 

641. Adhesion of earth. 340 

500. Adhesive strength of mortar (Table XLY).270-271 

751. Adjustment of grades at street-intersections. 421 

153. Advantage of sorting granite blocks at the quarry,. •. 87 

188. creosoting wood. Ill 

511. mixing mortar by machinery. 284 


705 



































706 


INDEX. 


ARTICLE PAGE 

221. Advantages of asphalt pavements. 137 

281. and coal-tar pavements . 168 

305. brick pavements. 179 

346. broken-stone pavements. 199 

281. coal-tar and asphalt pavements.168 

142. granite-block pavements. 82 

511. mixing concrete by machinery.... . 284 

396. rolling broken-stone pavements. 213 

13. smooth pavements. 6 

398. steam-rollers.. 214 

439. stone trackways... 237 

550. wheels . 307 

177. wood pavements. 104 

485. Age, effect of, on cement. 262 

505. strength of mortar. 276 

1030. Agreement, form of. 592 

Albertite (Table XIY A). 42 

584. Alignment of roads . 321 

1025. Alteration of manhole heads, etc..„.585 

92 a. American asphalturn. 41 

99e. bituminous rock. 49 

297. cost of construction. 176 

303. pavement, specifications for... 177 

300. pavements. 176 

473. natural cements, colors of.254 

473. specific gravity of.254 

257. Amount of asphaltic cement made by one ton of refined asplialtum. 151 
388. binding material required for broken-stone pavements... 211 

103a. bitumen in asphaltic paving-cement. 61 

bluestone used for street purposes in 1889 (Table XI).. . 34 

874. dirt produced by different pavements. 526 

25, 842. dirt removed from streets. 10 

70. granite used for street purposes iu 1889 (Table VII).... 29 

limestone used for street purposes in 1889 (Table XIII). 36 
412. material required to replace wear on broken-stone pave¬ 
ments . 220 

414. material used to replace wear on broken-stone pave¬ 
ments in England.220 

$1 at compound interest for a term of years (Table 

LXXXIX). 686 

414. material used to replace wear on broken-stone pave- 220 

ments in France.220 

207. < paving-cement manufactured from one ton of refined 

asphaltum. 151 

699. rainfall. 380 

refuse collected from city streets (Tabb LXXXVI).525 

404. rolling. 216 








































INDEX, 


707 


ARTICLE PAGE 

Amount of sandstone used for street purposes in 1889 (Table X). 34 

366. stone broken by band.205 

618. transverse rise required for different pavements (Table 

LXIV).. 334 

859. water required for sprinkling broken-stone roads.497 

913. water required for street sprinkling. 543 

101, 265a. Analysis of Bermudez aspbaltum.56, 161 

Analysis of California aspbaltum. 57 

99c. bituminous limestones (Table XV). 50 

102. sandstones. 58 

116. clay (Table XX). 65 

345. macadam pavement. 199 

99/. European bituminous limestone (Table XY). 50 

sandstone (Table VIII).. 33 

100/i. tbe residue of refined Trinidad aspbaltum. 54 

131. Tpihpkins Cove gravel. 75 

100& Trinidad aspbaltum crude. 52 

Alcatraz liquid asphalt. 45 

Utah liquid asphalt. 45 

Pittsburg asphaltic flux. 46 

Trinidad aspbaltum refiued. 55 

103a. and tests of aspbaltum. 59 

596. Angle of repose. 326 

645. of earths . 341 

Angles of slopes (Table LXVI).341 

Annual cost per bead of population for street maintenance in tbe 

United States (Table LXXXVII). 528 

43. Annual cost of pavements.. 16 

1045. structures. 683 

wood pavements in London (Table XXXI). 115 

89a. Appearance of aspbaltum. 38 

405. broken-stone pavements after being rolled. 215 

267. European bituminous limestone. 163 

100d. Trinidad aspbaltum. 52 

712. Arch culverts.. 390 

960. specifications for. 563 

713. thickness of (Table LXXY).390, 392 

878, 895. Area cleaned by machine brooms.527, 536 

878. Area cleaned by one man. 530 

793. covered by a barrel of Portland cement. 456 

375 . cubic yard of broken stone.207 

792 . cubic yard of concrete. 456 

256. cubic yard of prepared asphalt. 151 

171 . ton of granite blocks (Table XXYI)... 99 

302 778 ton of prepared rock-asphalt (Table LXXXIV) 

. 177, 441 

of tile-drains (Table LXXVII).395 















































703 


INDEX. 


ARTICLE PAGE 

699. Area of water-way of culverts. 378 

404. rolled by steam-roller per day. 216 

895. swept by machine-brooms. 536 

894. one man. 536 

674. Areas, sectional, of earthwork, formula for calculating. 363 

745. Arrangement of city streets.414 

751. street-intersections. 421 

streets with opposite sides at different levels. 426 

979. Artificial foundation, specifications for.569 

443. granite blocks. 238 

475. Portland cement. . 256 

822. stone curb and gutter, specifications for. 476 

815. curb. 473 

786. footpaths. 453 

796. specifications for.244, 458 

825. hollow curb.478 

450/. stone pavements. 243 

794. wear of. . 456 

279. and coal-tar. 167 

281. pavements, advantages of. 168 

285. cost of maintaining.169 

282. defects of. 168 

291. specifications for. 170 

296. block pavement, specifications for.175 

292. pavements.... .. 173 

294. cost of construction (Table XXXVI).... 175 

292. blocks, size of. 173 

96. cement. 44 

155. cement cushion-coat for stone blocks. 88 

243. Asphalt cement pavements. 145 

252. failure of. 147 

92a, 931?. Asphalte. 41 1 42 

103, 266. comprime. 59 , 162 

103, 778. coule. 59 

780, 781. footpaths, specifications for... .441, 443 

778. for footpaths... 440 

100 s, 103. Asphalt mastic.. .56, 58 

778, 781. mastic footway pavements in Paris.. .440, 443 

435. old, mixed with broken stone. 232 

one-coat pavement. 155 

874. pavement, amount of dirt produced by. 526 

19. and rain. 2 

894. area cleaned by one man . 536 

load drawn on, by a horse (Table LVII)... 302 

221 . pavements, advantages of,.. 137 

225. and street-car rails. 139 


» 















































INDEX. 709 


ARTICLE . PAGE 

261. Asphalt pavements and variations in temperature.137, 152 

232. cost of construction (Table XXXY). .141, 142 

887-889. cleaning...528, 534 

233. maintenance. 141 

222. defects of . 137 

218. difference between European and Ameri¬ 
can.». 135 

97a, 227. durability of.46, 140 

232. extent of, in 1890. 142 

252. failure of. . 147 

14. foothold on.'... 7 

340. foundation for. 144 

50. guarantee-period... 21 

366. in Europe. 162 

226. injured by illuminating gas. 139 

224. injured by water. 138 

223. injurious effects of sand on.... 138 

217. introduction of. 135 

27. life of. .... 11 

233. maintenance, cost of. 141 

265. by contract . 159 

222-261. maximum grade for.138, 152 

261. on grades . 153 

264a. , on surface of old pavements. 159 

19-21. slipperiness of.9, 10 

263. specifications for, on bituminous base.... 158 

264. specifications for, on hydraulic concrete 

base. 159 

262. specifications for, Trinidad. 153 

897. squilgees for. 537 

1039. tools used in the construction of. 654 

228. traffic sustained by.. 140 

transverse rise for (Table LXIY).334 


253. Trinidad composition of the wearing sur¬ 


face. 150 

231. wear of. 141 

103a. paving-cement, amount of bitumen in. .. . 61 

256 . area covered by a cubic yard of. 151 

256. - weight of a cubic yard. 151 

253 . paving, proportion of the materials used... 150 

two-coat pavement. 154 

210 . wood pavement. 121 

90, 90a, 95c. Asphaltene. 39-44 

470. Asphaltic cement for concrete. 253 

96, 97, 100c, 102. Asphaltic cement ... .44, 46, 55, 58 

99 ^ paving compounds. 48 

99 materials. 48 














































710 


INDEX. 


ARTICLE PACE 

88 . Asphaltum. 38 

103a. analyses and tests of. 59 

92a, 102. Asphaltum, American.41-57 

101-265a. Bermudez.56—161 

265a. analysis of. 161 

265a. composition of the wearing-surface with 162 

89c. characteristics of. 38 

90. composition of.39-42 

94. crude... 43 

104. Cuban, price of (Table XVII). 61 

composition of. 42 

220 . different varieties, cost of preparing the. 136 

92. distribution of. 40 

96a flux for. 44 

104. imports of, into the United States in 1890 (Table 

XIX). 62 

Mexican. 42 

Oklahoma. 42 

Peruvian. 42 

93. nomenclature... 41 

92. occurrence of. 40 

104. prices of, in New York in 1893 (Table XVII)_ 61 

production in the United States (Table XVIII).. 63 

95. refining. 43 

89c. specific gravity of (Table XXIV.). 39 , 77 

89. varieties of. 33 

100 . Trinidad. 51 

analyses of. 52 

100 c. characteristics of refined. 52 , 55 

100 d. of crude. 52 

100 c, 243. preparation of. 53 ? 145 

104. price of (Table XVII). 61 

100 a. refined, specific gravity of. 55 

100 a. composition of. 55 

257. number of cubic yards to one ton 151 

100 . source of. 50 

105. uses of. 

weight of (Table XXIV). 77 

450/. Artificial stone. 243 

1012. Assignment of contract. 577 

153. Assorting granite blocks at the quarry, advantage of. 87 

410. Atmospheric changes, effect of, on pavements.220 

418. Austria, amount of material used in, to replace wear on broken- 

stone pavements... 221 

1036. Aveliug & Porter steam-roller.650-652 

Average width of sidewalks in various cities (Table LXXXII).... 422 










































INDEX. 


711 


B. 

ARTICLE PAGE 

629. Balancing transverse of earthwork.337 

881. Baltimore, street-cleaning in.531 

86 . Basalt, description of. 37 

resistance to crushing of (Table XXIY). 77 

specific gravity of (Table XXIV). 77 

weight of (Table XXIV). 77 

897. Bass brooms. 537 

136. Belgian block pavement. 81 

172. cost of construction (Table XXVIII). ... 99 

137. defects of. 81 

138. specifications for. 81 

418. Belgium, cost of maintaining broken-stone pavements in.221 

572,940. Bench-marks.312, 556 

32. Benefit, economic, of good pavements. 13 

162. Berea sandstone. 91 

265a. Bermudez asphalt. 161 

745. Best arrangement of city streets. 414 

565. road.311 

459. Betou. 247 

1029. Bid, form of. 591 

1028. Bidders, instructions to. 587 

386. Binding. 210 

391. effect of. 212 

388. using large quantities. 211 

390. necessity of. 211 

430. power of clay. 230 

389. proportions adopted by the French engineers. 211 

388. quantity of.211 

897. Birch brooms.,.537 

101-265a. Bermudez asphaltum.56, 161 

88-94. Bitumen .38, 42 

89a. earthy. 38 

896. elastic.%. . 38 

89c. hard. 38 

103a. amount in asphaltic paving-cement. 61 

94. liquid...42-45 

specific gravity of (Table XXIV).39, 77 

weight of (Table XXIV). 77 

91. origin of. 40 

89c. specific gravity of. 39 

96, 160. Bituminous cement, composition of.44, 89 

161. cost of. 90 

160. for filling joints. 89 

161. manner of using. 90 















































712 


INDEX. 


ARTICLE PAGE 

242, 263. Bituminous concrete...145, 158 

259. limestone pavements, experience with, in Wash¬ 
ington...... 152 

277. pavements in the United States.166 

specific gravity of (Table XXIV). 77 

268. test for. 163 

92a, 94, 996. limestones.41-42, 49 

268. appearance of European. 163 

99/. how used. 49 

270. preparation of. 164 

434. macadam. 231 

297. rock, American..176 

303. pavements, specifications for. 177 

104. production of, in the United States (Table 

XVIII). 63 

99d. rocks, analyses of European (Table XV). 50 

102. sandstones, analyses of. 58 

99y. in America. 50 

998. in Europe. 50 

998. preparation of. 50 

456. Blast-furnace slag for foundations of pavements. 246 

330. used for bricks.. 187 

450a. paving. 241 

663. Blasting.\ .... . 357 

292. Block pavement of asphalt.... 173 

182. Blocks sapless cedar . 109 

81. Bluestone, amount used for street purposes in 1889 (Table XI). 34 

831. bridge-stones, specifications for. 483 

818. curb. 474 

818. specifications for. 474 

78. description of. 32 

776, 1018. flagging, specifications for...„ . 440-583 

774. for footpaths.•.439 

resistance to crushing (Table IX). 33 

specific gravity of (Table IX).7. 33 

uses of. 32 

value of, used for street purposes in 1889 (Table XI).... 34 

value per cubic foot (Table XI). 34 

weight of (Table IX). 33 

1558. Bogs, embankments across . 351 

1007. Bond for faithful performance of work. 576 

1031. form of. 601 

1021. indemnity. 584 

Books kept by cantonniers. 512 

632. Borrow pits... 338 

636. form of. 338 

637. staking out. 339 















































INDEX. 


713 


ARTICLE 

133. Boston, cobblestone pavements in. 

882. street cleaning in.. 

711. Box-culverts. 

711. dimensions of (Table LXXIY) 

597. Brakes, effect of. 

Breaches of highway law. 

362. Breaking stone by hand. 

365. cost of. 

364. machinery. 

367. cost of. 


60. tests of materials. 

954. Breast-walls, specifications for... 

Brennan’s stone-crusher. 

107. Brick... 

64. absorptive power of (Table V). 

330. blast-furnace slag. 

common hard, resistance to crushing of (Table XXIV) 

specific gravity of (Table XXIV). 

weight of (Table XXIV).... 

688. drains... 

784. footpaths. 


785. 

828. 

329. 


968. 


324. 


877. 


322. 

334. 

304. 

305. 

326. 

320. 

306. 

307. 

308 

309. 

316. 

27. 

318. 

601. 

331-334. 

327. 

64, 119. 


specifications for... 

gutters, specifications for. 

iron. 

masonry, specific gravity of. 

specifications for. 

weight of (Table XXIV). 

McReynold’s patent. 

pavement, cost of cleaning. 

transverse rise for (Table LX1V). 

variety of systems. 

variations in specifications for. j. . 

pavements.. 

advantages of... 

Charleston plan. 

cost of (Table XXXVIII). 

defects of... 

durability of. 

experience with. 

failures of. 

foundation for. 

life of..... 

manner of laying... 

maximum grade for. 

specifications for. 

Wheeling plan. 

paving, absorptive power of (Table V aud Table XXI) 


PAGE 

... 79 

... 531 
... 388 
... 390 
.. 326 
... 511 
... 204 
... 205 
... 205 
... 205 
... 24 
... 561 
... 631 
... 63 

... 26 
.. 187 
... 77 

... 77 
... 77 
... 373 
... 451 
.., 452 
,... 480 
... 187 
... 77 

... 565 
... 77 

.. 186 
... 527 
... 334 
... 184 
... 193 
... 179 
... 179 
... 186 
... 184 
... 179 
... 181 
... 181 
... 181 
... 182 
... 11 
... 183 
... 327 
187-194 
... 186 
. 26, 57 



















































714 


INDEX. 


ARTICLE 


PAGE 


117. Brick, paving, characteristics of good. 66 

323. Halwood block. 185 

114. manufacture of. 65 

prices of (Table XXI). 68 

314. quality of. 182 

111. quality of clay for. 63 


119. resistance to crushing of (Tables XXI A, XXIV) 

69, 67, 77 


313. shape of.... 182 

313. size of. 182 

119. specific gravity of (Table XXIV and Table XXI)_67-68 

322. the Hayden. . 184 

117, 119. weight of (Table XXI and Table XXIV).68-77 

pressed, resistance to crushing of (Table XXIV). 77 

specific gravity of (Table XXIV). 77 

weight of (Table XXIV). . 77 

soft inferior, resistance to crushing of (Table XXIV). 77 

specific gravity of (Table XXIV)..... 77 

weight of (Table XXIV)... 77 

Stourbridge fire, resistance to crushing of (Table XXIV)_ 77 

specific gravity of (Table XXIV). 77 

weight of (Table XXIV). 77 

118. tests of. 66 

Ohio paving (Table XXI A)... 69 

Brickwork in cement-mortar, resistance to crushing (Table XXIV). 77 

575. Bridge sites, selection of . 315 

720. specifications for. 402 

720. substructure of...399 


830. stones. 4 si 

831. specifications for. 483 

421. Bridgeport, Conn., broken-stone pavements in. .223 

715. Bridges. 396 

858. examination of. 497 

716. live loads. 396 

718. materials for. 397 

716. proportioning of. 396 

933. setting out. 552 

435. Broken stone, and old asphalt... 232 


375. area covered by a cubic yard. 207 

373. determination of the voids in . 207 

410. pavement, action of the weather on. 220 

874. amount of dirt produced by. 526 

859. water required for sprinkling.. 497 

894. area cleaned by one man. 536 

360. breaking the stone. 204 

877. cost of cleaning. 527 

406. rolling... 217 












































INDEX. 


715 


ARTICLE p AGE 

344. Broken-stone pavement, defects of Telford’s system. 198 

408. difference in the cost of European and 

American. 219 

410. effect of horse’s hoofs on.220 

410. wheels on. 220 

412. mud on. 220 

load drawn by a horse on (Table LVII)... 302 

405. manner of applying the roller.217 

381. sand core for. 209 

transverse rise for (Table LXIY).334 

338. Tresaguet’s method. 195 . 

335. pavements. 195 

346. advantages of..... . 199 

396. rolling. 213 

414. amount of material required to replace 

wear. 220 

404. amount of rolling required. 216 

405. appearance of, after being rolled. 216 

413. average annual loss of thickness. 220 

381. care of. 209 

393 . compacting the stone. 212 

393 . by the traffic. 212 

397 . horse-rollers. 212 

398. steam-rollers....214 

407. cost of (Tables XLI and XLII). 217 

418, 860. maintenance.221-498 

347. defects of. 199 

350, erroneous methods of construction. 200 

349 . essentials necessary to successful construc¬ 
tion . 200 

379 . failure of. 209 

15. foothold on. 7 

421. in Bridgeport, Conn. 223 

420. Chicago. 222 

413 . loss of thickness. 220 

340. MacAdam’s method.197 

850. maintenance of.491 

415 . manner of restoring thickness. 220 

001. maximum grade for.327 

419 . modern, in England..'..222 

351 . quality of stone for. 201 

417 . recoating, when it should be done. 221 

861. repair of. 498 

359 shape of stones for. 204 

357 . size of stone for. 204 

423 . specifications for. 227 

3 g 3 . ' spreading the stone. 218 















































716 


INDEX. 


ARTICLE PAGE 

339. Broken-stone pavements, Telford’s method. 196 

378. thickness of. 208 

384. layers. 210 

1036. tools employed in the construction. 628 

1037. maintenance. 653 

traction on (Table L).. 295 

392. watering, use of. 212 

63, 409. wear of... .26, 219 

382. quantity required per mile for different widths (Table 

LX). 209 

1019. specifications for.. 583 

387. screening of... 211 

372, 461. voids in. 206-248 

374. weight of. 207 

883. Brooklyn, N. Y., street cleaning in... 533 

897. Brooms, bass.... . 537 

897. birch. 537 

prices of. 662 

897. rattan. 537 

897. steel-wire. 537 

1017. Bulkhead, specifications for a. 579 

C ' 

674. Calculating amount of earth-work. 363 

676. the half-widths and areas of earth-work. 364 

102. California asphaltum. 57 

104. bituminous rock, price of.. 61 

102 .* analysis of. 57 

Cantonuiers, absence, fines for. 513 

annual gratuities. 513 

appointment of. 507 

books. 512 

chief. 507 

classification of. 512 

compulsory attendance of. 511 

distinctive mark. 512 

duties of. 506 

fines on account of absence. 513 

gratuitous assistance to travellers by. 511 

indemnity for removal of. 513 

leave of absence. 512 

866 . means of verifying absence of. 512 

regulations for.. 506 

salary of. 512 












































INDEX. 


717 


ARTICLE PAGE 

866 . Cantonniers, surrender of books and distinctive marks on dismissal 

of a. 512 

surveillance over breaches of the highway law.. 511 

tools furnished by the.... . 511 

to the. 511 

keeping in repair by. . 512 

working hours of . 510 

Capacity of drill-holes (Table LXYIII). 358 

1033. scrapers. 605 

sprinkling-carts. 535 

1036. stone-crushers.628 

39. Care of pavements. 14 

1033. Carts, capacity of. 611 

earth. 611 

898. for street dirt.537 

sprinkling, capacity of. 535 

price of. 535 

1042. Cast-iron gutter-crossings. 678 

specific gravity of (Table XXIY). 77 

984. specifications for.... . 570 

1042. Catch-basin covers. 676 

761. Catch-basins. 428 

1018. specifications for.583 

704. -pools, use of. 382 

696. -water ditches. 377 


951. specifications for. 561 

858, 869. Causes producing dirt .495-522 

208. Cedar-block pavements. 121 

216. specifications for. 132 

482. Cement, activity of . 260 

485. age, effect of. 262 

,473. American natural, specification. 254 

requirement for.254 

amount of water absorbed by (Table XLIY). 262 

475. artificial Portland. .255 

96. 100, 102. asphalt..44-55-58 

160. bituminous, composition of. 8 9 

161. cost of . 

161. manner of using. 90 

473, 479. color of American natural.254-259 

510. data for estimates. 284 

483. effect of variations of temperature on. 2 ^0 

475 English Portland, specific gravity of (Table XXIV)-77-255 

476 ; weight of (Table XXIV).77-257 

790. expansion of . 

French Portland, weight of (Table XXIY). 47 

473. hydraulic. 
















































718 


INDEX. 


ARTICLE PAGE 

490. Cement, measuring fineness of... 265 

494. -mortar, composition of. 268 

474. natural Portland. 255 

706. pipe for culverts. 383 

707. cost of. 387 

dimensions of.387 

161. Portland and iron slag for filling joints. 90 

476. characteristics of.257 

475. effect of sand on.257 

509. English specifications for. 283 

476, 489. fineness of.257-264 

477. necessity of testing. 258 

476. specific gravity of.258 

476. tensile strength of. 258 

973. test for. . 567 

476. weight of. 257 

482. quick- and slow-setting, definition of. 260 

Roman, specific gravity of (Table XXIV). 77 

weight of (Table XXIV). 77 

973. Roseudale, test for. 567 

473. specific gravity of American natural.254 

972. specifications for. 567 

473. strength of American natural. 254 

492. testing machine. 266 

477. ' necessity of. 258 

477. tests. 258 

973. specifications for. 567 

473. weight of American natural (Table XXIV).77-254 

45. Census, traffic... 17 

48. form of. 19 

962. Centring, specifications for. 564 

Chalk, resistance to crushing of (Table XXIV). 77 

specific gravity of (Table XXIV). 77 

weight of (Table XXIV). 77 

89a. Chapapota. 

457. Character of concrete for pavement foundations. 247 

453. natural soils. 245 

543. vehicles. 305 

473. Characteristics of American natural cements. 254 

89. asplialtum. 38 

268. European bituminous limestone... 163 

117. good paving-brick. 66 

499. mortar. 270 

476. Portland cement. 257 

100^. Crude Trinidad asplialtum. 52 

lOOn. refined Trinidad asphaltum. 55 

lOOd. Crude. 53 


















































INDEX. 


719 


ARTICLE 

44b. Charcoal roads. 

826. Charleston plan of brick pavements 

29. Cheapest pavement. 

100a. Cheese pitch. 

122, 188. Chemical treatment of wood.... 

182a, 450c. Chest. 

420. Chicago, broken-stone pavements in 

Chief cautonuier. 

862. foreman, duties of. 

819. Circular curb. 


PAGE 

... 244 
,186 
,.. 11 
... 51 

74, 111 
.76-242 
.. 222 
,.. 507 
... 499 
. . 475 


pipes, discharging capacity of (Table LXXXVIII).895 

81. City ownership of street-car tracks. 18 

744. streets. . 414 

878. amount of refuse collected from (Table LXXXYI). 525 

746. best arrangement of. 414 

749. grade of. 7 420 

748. maximum grade of, in various cities (Table LXXXI)_ 420 

747. - width of (Table LXXXII). 420 

1005. Claims, payment of. 575 

949. Classification of earth-work .560 

107. Clay. 68 

116. analysis of (Table XX). 66 

426. binding power of.280 

113. color of . 65 

108. composition of.„. 63 

450c?. Florida. 242 

111. for paving-bricks. 64 

426. proportion of, to gravel. 229 

835. roads, improving of.485 

836. maintenance of. ..486 

836. trees on.486 

639. shrinkage of . 389 

686. soils, drainage of .... 371 

specific gravity of (Table XXIY). 77 

weight of (Table XXIV). 77 

with gravel, specific gravity of... 77 

weight of . 77 

127. sand. 75 

1011. Cleaning up, specifications for. . 577 

40. of pavements. 15 

126. Cleanness of sand, to test. 75 

868. Cleansing of streets. 521 

877. cost of.. . 527 

875. methods employed... 526 

944. specifications for. 558 

1040. tools employed for. 662 

944. Clearing, specifications for. .558 




















































720 


IKDEX. 


ARTICLE PAGE 

1032. Clearing, tools for.604 

884. Cleveland, Ohio, street cleaning in. 533 

450/i. Clinkers. 244 

945. Close cutting, specifications for. 558 

279. Coal-tar and asphalt. 167 

281. pavements, advantages of. 168 

284. cost of maintaining. 169 

282. defects of. 168 

291. specification for. 170 

278. pavements. 166 

827. Cobblestone gutters, specifications for laying. 479 

133. pavement. 79 

172. cost of (Table XXX). 100 

133. in Boston. 79 

133. Philadelphia. 79 

166. on steep grades. 91 

135. specifications for. 79 

Coefficients for retaining-walls (Table XXXI).. .... 408 

352. of quality of stones for broken-stone pavements (Table 

XXXVIII). 203 

982. Cofferdams, specifications for.„. 569 

687. Collars for tiles. 372 

89. Color of asphaltum. 4 .38-52 

473, 479. cements.. .254, 259 

113. clay.. 65 

65. granite. 27 

74. sandstone. 31 

86 . trap. 36 

450. Combinations of wood and iron. 241 

Common hard brick, resistance to crushing of (Table XXIV). 77 

specific gravity of. 77 

weight of. 77 

472. lime. . 253 

1001. Commencement of work. 574 

79. Commercial names of sandstones. 33 

393. Compacting the broken stone. 212 

104. Comparative prices of asphaltum in 1889 (Table XVII). 61 

rank of pavements (Table IV) . 21 

15. safety of pavements. 7 

1002. Completion, time of . 574 

90. Composition of asphaltum (Table XIV«).39-42 

160. bituminous cement. gt) 

494. cement-mortar. 268 

108. clay... 63 

459. concrete. 047 

872. mud (Table LXXXV). 523 

872. street dust. 526 

















































INDEX. 


791 

I /v jL 


ARTICLE PAGE 

782. Compressed asphalt tile footway-pavement. 450 

4<>8. Compressive strength of concrete.251 

502. mortar. 273 

Compulsory attendance of the cantonniers. 511 

623. Concave cross-section.336 


466. Concrete, amount of ramming required. 250 

470. and furnace-slag. 253 

792. area covered by a cubic yard.456 

242-263. bituminous.145-158 

460. character of, for pavement foundations.248 

459. composition of. 247 

468. compressive strength of. 251 

469. cost of. 252 


459. definition of. 247 

459. essentials necessary to the manufacture of good. 247 

791. footpaths. .... 454 

795. specifications for.458 

460. for pavement foundations.248 

470. ' formed with asphaltic cement. 253 

154. foundations, thickness of. 88 

466. laying of.250 

436. macadam.-. 232 


465. mixing of. 250 

machiue, price of.660 

471. mortar for. 253 

461, 462. proportions of ingredients. 248 

459 . quality of stone for. 247 

464. quantity of materials required for one cubic yard. 249 

463 . water required for. 249 

466. ramming of. 250 

127. sand for. 75 

459 . size of stone for.. 248 

460. specific gravity of (Table XXIY).77, 248 

512-516, 977. specifications for.285, 288, 568 

460, 468. strength of.248, 251 

458 . thickness of. 247 

467. transverse strength of.. 251 

461. usual proportions of ingredients. 248 

457 . weight of (Table XXIV).<7, 24< 

791 rammers for. -.456 

28. Considerations concerning cost of pavements . 11 

942 . tests of materials.....557 

governing location of roads. 309 

42. Consequential damages,.*. 15 

444. Construction of plank roads .238 

739 roads along the seashore or margins of rivers. 410 

404 wood pavements, essentials necessary to the success¬ 
ful. 110 


















































722 


INDEX. 


ARTICLE PAGE 

593. Construction of profile. 324 

560. Contour lines... 310 


625. transverse on hillside roads ...336 

618. of roadway.334 

756. streets. 425 

1003. Contract, forfeiture of..,. 574 


1030. form of. 592 

1014< prices in. 577 

1012. subletting of . 577 

913. Contracts. 558 

476. Contraction of Portland cement.258 

988. Contractor defined.. 570 

989. notice to.570 

1012 . personal attention of. 577 

621. Convexity, excessive, objections to. 334 

447. Corduroy roads. 240 

381. Core for broken-stone pavements. 209 

43. Cost, annual, of pavements. 16 

1045. structures. 683 


33. 

44. 

161. 

363. 

320. 

469. 

300. 

296«. 

232. 

172. 

407. 

172 . 

172. 

432. 

172. 

205. 

899. 

188. 

710. 

688 . 

840. 

672 . 

706. 

668 . 


wood pavements in London (Table XXXI). 115 

per head of population for street maintenance in the 

United States (Table XXXVII). 531 

first, of pavements. 13 

gross, “ “ 13 

of bituminous cement. 90 

breaking stone by hand.. 205 

brick pavements (Table XXXVIII).183, 184 

concrete. 252 


construction of American bituminous-rock pavements ..... 177 
asphalt-block pavements (Table XXXVI) .. 176 

asphalt pavements (Table XXXV'.142 

Belgian block pavements (Table XXVIII) . 97 

broken stone pavements (Table XLII). 217 

cobblestone pavements (Table XXX). 100 

granite-block pavements (Table XXVII)... 98 

gravel pavements (Table XLIII).231 

sandstone pavements (Table XXIX). 99 

wood pavements (Table XXXIII). 119 


crematories. 

creosotiug wood. 

different forms of culverts., 

drains.... ... 

drain-tiles (Table LXXVII) 
earth roads.. 


037 

113 

388 

373 

395 

487 


-work 


361 


earthenware culvert-pipe 
excavating rock. 


383 

359 














































INDEX. 


723 


ARTICLE PAGE 

742. Cost of fencing. 412 

709. iron pipe-culverts (Table LXXI1I). 388 

233. maintaining asphalt. 142 

418, 860. broken-stone pavements .....221, 498 

841. earth roads. 488 

169. granite-block pavements. 94 

403. steam rollers. 215 

206. wood pavements (Tables XXXI and XXXIV) 

115, 120 

905. melting snow. 539 

886. Cost of operating machine brooms.. 533 

1033. ploughs.605 

368. stoue-crusliers. 205 

28. pavements, considerations concerning. 11 

446. plank roads. 240 

Portland-cement pipe (Table LXXII). 568 

220. preparing the different varieties of asphalt. 136 

371. quarrying stone (Table XXX).206 

900. removing snow . 538 

406. rolling . 217 

104. sandstone pavements. 91 

41. service of pavements. 15 

369, 370. stone-crushers.206, 630 

371. crushing (Table XXXIX).207 

877, 893. street cleaning.527, 536 

915. sprinkling. -••• 

893. sweeping. . 536 

439. trackways. 236 

707. vitrified pipe culverts (Table LXXI). 38 7 

5. wagon transportation (Table I).2, 681 

878. per capita for street maintenance (Table LXXXVII).528 

555. Country roads, location of. 309 

862. County engineer. 501 

650. Covering of slopes .344 

1042. Covers for catch-basins..676 

899. Crematories, cost of. 537 

122,188. Creosoting wood. ^4 

588. Crookedness, objections to. 323 

573. Cross-levels....;.312 

677. -section of earth-work. 364 

770. -slope of footpaths. 438 

1033. -ties, number per mile.614 

830. Crossing-stones. 481 

830. dressing of.481 

830. quality of. 481 

832. relaying...483 

831. specifications for. 483 
















































724 


INDEX. 


ARTICLE PAGE. 

755. Crowns in gutters. 425 

94. Crude asphaltum. 43 

369, 370. Crushers, capacity of.206, 630 

369. 370. stone, cost of.206, 630 

367. operating.205 

370. horse-power required for.206, 630 

369. size of.206, 630 

368. * wear of. 205 

Crushing, resistance to, of bassall (Table XXIV). 77 

brick (Table XXIV). 77 

cast-iron (Table XXIV). 77 

chalk (Table XXIV). 77 

common bard brick (Table XXIV). 77 

69. granite (Table VI). 28 

lead (Table XXIV). 77 

85. ligonier. 36 

limestone (Table XXII). 35 

materials (Table XXIV). 77 

119. paving-brick (Table XXIV). 77 

pressed brick (Table XXIV). 77 

sandstone (Table IX). 33 

soft brick (Table XXIV). 77 

Stourbridge (Table XXIV). 77 

trap-rocks (Table XIV). 37 

wrought iron (Table XXIV). 77 

wood (Table XXII). 73 

371. stone, cost of (Table XXXIX). 207 

60. tests . . 24 

104. Cuban asphaltum, price of (Table XIVa and Table XVII).42, 61 

Cubic contents of embankments and excavations (Table LXX).369 

377. yard of broken stone, area covered by a. 208 

464. concrete, materials required for. 249 

153. Culling of stone paving-blocks. 87 

697. Culverts. 378 

712. arch. 390 

699. area of water-way. 378 

711. box. 388 

711. dimensions of. 388 

706. cement pipe for. . 383 

707. cost of cement pipes for. 387 

707. vitrified pipe... 387 

970. dry box, specifications for. 500 

706. earthenware pipes for. 383 

702. formula for calculating the area of water-way. 381 

708. iron pipes for. 387 

932. length of. 551 

705. materials for.. 382 

















































INDEX. 


725 


%■ 


ARTICLE PAGE 

971. Culverts, pipe, specifications for. 566 

955, 960. specifications for.562, 566 

931. staking out. 550 

820. Curb, setting, specifications for. 475 

937. stakes for. 555 

1018. specifications for. 580 

813. Curbing. 473 

815. artificial stone. 473 

822. specifications for. 476 

817, 819. bluestone, specifications for.473-475 

818. circular. 475 

813. dimensions of. 473 

815. fire-clay. 473 

816. granite, specifications for. 473 

825. hollow, of artificial stone. 478 

815. iron. 473 

814. materials employed for. 473 

823. old, dressing of.478 

824. resetting, specifications for. 478 

813. setting of. 473 

585. Curves... 321 

586. grade on. 321 

929. staking out of. 550 

610. vertical use of. 331 

587. width of roadway on.323 

589, 590. Curving and straight roads, difference between.323 

155. Cushion-coat for granite blocks. 87 

155. quality of sand for. 87 

D 

1009. Damage and loss. 576 

42. Damages, consequential . 15 

1004. for non-completion. 575 

842. Data required to calculate the value of improvements.488 

558. for the location of roads. 309 

181. Death-rate and wood pavements. 107 

849. Decreasing the length, profit of. 490 

42. Defective pavements, cost of. 15 

998. work. 572 

222. Defects of asphalt. 137 

137. Belgian-block pavements. 81 

306. brick pavements. 179 

347. broken-stone pavements. 199 

282. coal-tar and asphalt pavements. 168 

393. compacting broken stone by the traffic .212 

:846. existing roads. 489 
















































726 


INDEX. 


ARTICLE PAGE. 

143. Defects of granite-block pavement. 82 

345. McAdams pavements. 199 

186. plank and sand foundation. 110 

454. sand foundations.... 246 

344. Telford’s pavements. 198 

178. . wood pavements... 104 

627. Definition of earth-work. 337 

852. maintenance. 493 

88 . Deposits of asphaltum. 38 

Depots for broken stone .501 

666 . Depth of hole drilled by hand. 359 

667. machine drills. 359-626 

88 . Description of asphalt. 38 

78. bluestoue. 32 

concrete. 493 

65. granite. 27 

82. limestone. 34 

74. sandstones. 31 

941. specifications. 557 

• Designation of grades (Table LXII). 330 

10. Desirability of pavements... ,5 

55. Destruction of pavements. 22 

996. Details, right to alter. 571 

595. Determination of grades.. 326 

604. the maximum grade. 328 

372, 461. voids in broken stone.. 206-248 

885. Detroit, street cleaning in. 533 

995. Deviations from specifications... 571 

Diameter of horse-rollers....... 647 

steam “ ...649 

689. tiles. 373 

wheels. .. 307 

218. Difference in cost between American and European asphalt. 135 

408. of broken-stone pavements in Europe and Amer¬ 
ica....,. 219 

189. Dimensions of blocks for wood paving. 113 

711. box-culverts (Table LXXIX). 390 

313. bricks for paving. 68-182 

813. curbing . 473 

466. rammers for concrete. 21 

146. stone blocks for paving. 84 

1036. crushers... 631 

wooden bridges (Tables LXXIX, LXXX). 400 

707. weight, and prices of vitrified pipe. 387 

874. Dirt, amount produced by different pavements.526 

23. and durability of pavements. 10 

898. carts. 537 





















































INDEX. 


727 


ARTICLE PAGE 

809. Dirt-producing causes.522 

Discharging capacity of pipes (Table LXXYIII). . 395 

991. Dismissal of incompetent workmen.571 

1023. Disposal of old materials.584 

900. snow.. 538 

899. street dirt. 537 

924. Distance apart to plant trees. 548 

283. Distillate pavements in Washington, D. C. 169 

Distinctive marks of cantonniers. 512 

92. Distribution of asphaltum. 40 

692. Ditches, cleaning out. 375 

692. side. 375 

685. Division of natural soils with reference to draining.... . ...371 

689. Drain-tiles, dimensions of. 373 

682. Drainage, kinds of. 371 

452. necessity of. 245 

655. of embankments. 349 

452. - foundations. 245 

803. grade-walks.465 

647. side-slopes. 342 

651. slopes.346 

758. sub-foundation of streets. 427 

693. the surface of roads. 375 

759. streets. 428 

762. -surface at street-intersections. 431 

683. Draining, methods employed for. 371 

1034. tools for. 021 

686 . Drains.372 

688 . cost of.373 

691. fall of.373 

form of. 374 

687. materials for. 372 

686 . mitre. 371 

687. outlets, protection of. 372 

950. specifications for. 061 

934. staking out... 053 

689. tile. 3/3 

688 . tiles, cost of. 373 

size of (Table LXXVII). 395 

weight of (Table LXXVII)... 395 

532. Draught of horses. 300 

830. Dressing of crossing-stones. 48 J_ 

149. stone paving-blocks. 85 

773 . stones for footpaths. 439 

Drill-holes, capacity of (Table LXVIII). 308 

663. depth of.308 

663. diameter of. 358 






















































728 


INDEX. 


ARTICLE PACE 

Drills, steam, price of . 626 

970. Dry box-culverts, specifications for. 566 

969. masonry, specifications for. 565 

721. Dry-stone retaiuing-walls. 402 

Dump-cars, capacity of. 613 

. 670. -wagons.360-615 

25. Durability and dirt. v 10 

61. methods of testing. 25 

779. of asphalt footpaths. 441 

27, 97a, 227. pavements.11, 46, 140 

27, 307. brick pavements...11, 181 

27, 167. granite blocks.11, 93 

23. pavements. 10 

27, 193. wood pavements. .11, 115 

Duration of a horse’s daily labor and maximum velocity unloaded 

(Table LIV).301 

872. Dust, street, composition of. 523 

899. removal of. 537 

866 . Duties of the cantonniers. 506 

862. chief foreman. 499 

862. foremen. 499 

518. Dynamometer experiments.289, 297, 306 

E 

641. Earth, adhesion of. 340 

645. angle of repose of. 341 

647. effect of moisture on. 342 

669. loosening of. 360 

645. natural slopes of. 341 

840. roads, cost of. 487 

841. maintaining.488 

load drawn by a horse on (Table LVII). 302 

transverse rise for (Table LX1V)..'. 334 

839. use of scraping-machine on.487 

640. settlement of. 339 

specific gravity of (Table XXIY). 77 

642. stability of. 349 

670. transport of. 360 

weight of (Table XXIY). 77 

674. -work, calculating the amount of. 363 

949. classification of. 560 

<>i2. cost of. 361 

677. cross-sections. 364 

627. definition of. 337 

634. equalizing of. 333 














































INDEX. 


729 


ARTICLE PAGE 

641. Earth-work, failure of.367 

679. formulas for calculation of sectional areas. 366 

676. half-widths and areas.364 

949. measurement of. 560 

651. slips of. 344 

table of cubic contents... 369 

629. trausverse balauciug. 337 

706. Earthenware pipe for culverts. 383 

89a Earthy bitumen. 38 

32. Economic benefit of good pavements. 13 

34. Economies of pavements, the relative. 14 

31. Economy and public bodies. 12 

557. of motive power.309 

13. smoothness. 6 

410. Effect of atmospheric changes on pavements. 220 

388. binding. 211 

392. excessive watering.212 

507. - frost upon mortars..217 

581. grades upon the load drawn by horses (Table LV1II)- 303 

410, 1044. horses’ feet on pavements.220-683 

647. moisture on earth. 342 

544. narrow tires. 305 

7 . reducing the cost of wagon transportation. 4 

475 . sand on strength of Portland cement.. 256 

504. size of grain of sand on strength of mortar (Table XLVIII) 276 

386. using large quantities of binding. 210 

554. vehicle springs . 308 

410. wheels on pavements. 220 

615. width on cost of maintenance. 332 

895. Elastic bitumen. 38 

847. Eliminating unnecessary grades, profit of..... .489 

652. Embankments .. 346 

658. across bogs. 351 

657. marshes. 349 

655. drainage of. 349 

653. formation of. 346 

659. on hillsides. 352 

656. over plains. 349 

654. side-slopes of:. 348 

948 . specifications for. 559 

987. Engineer defined.*. 

990. Engineer’s marks, preservation of. 571 

414. England, amount of material used in, to replace wear on broken- 

stone pavements. 220 

100c. Epuree. 51 

628. Equalizing earth-work. 337 

350. Erroneous methods of constructing broken-stone pavements. 200 















































730 


INDEX. 


ARTICLE PAGE 

452. Essentials necessary to the formation of good foundations. 245 

349. successful construction of broken-stone 

pavements. 201 

459. to the manufacture of good concrete. 247 

009. Establishing the grade. 331 

1043. Europe, prices of labor in. .680 

266. European asphalt pavements . 162 

259. experience with, in America. 152 

268. bituminous limestone, appearance of. 163 

268. characteristics of.*. 163 

rocks, analyses of. 50 

1005. Evidence of the payment of claims... 575 

858. Examination of bridges. 497 

577. Examples in location. . . 316 

662. Excavating rock. 357 

978. Excavation, foundation, specifications for. 569 

31, 57. Excavations in streets.13, 23 

621. Excessive convexity, objections to... 334 

392. watering, effect of.,.... 212 

476, 790. Expansion of cement. 258-454 

190. wood-paving blocks. 114 

308. Experience with brick pavements. 181 

259. European asphalt pavements in America_ 152 

84, 165. limestone paving.35, 91 

662. Explosives, quantity required (Table LXVII). 357 

232. Extent of asphalt pavements in 1890 (Table XXXV).141-142 

Belgian block pavements (Table XXVIII). 99 

brick pavements (Table XXXVII). 184 

cobblestone pavements in 1890 (Table XXX). 100 

granite “ (Table XXVII). 98 

gravel “ (Table XLIII). 231 

macadam “ (Table XLII). 218 

sandstone pavements in 1890 (Table XXIX). 99 

wood pavements in 1890 (Table XXXIII). 119 

F 

252. Failures of asphalt pavements. 147 

309. brick pavements. 181 

641. earth-work. 340 

727. retaining-walls. 407 

380. thin broken-stone pavements.209 

186. wood pavements. 110 

1007. Faithful performance of work, bond for. 576 

691. Fall of drains. 373 

22. Falls of horses, kinds and causes of. 10 













































INDEX. 


731 


ARTICLE PAGE 

1036. Farrell stone-crusher. 632 

Feldspar, specific gravity of (Table XXIV). 77 

weight of (Table XXIV). 77 

Feldspatliic rock. 27 

741. Fencing. 412 

742. cost of... 412 

743. specifications for.. ... 412 

354. Fieldstoue. 202 

280. Filbert vulcanite pavement. 167 

loO, 192. Filling for joints in pavements.89-114 

592. Final location. 324 

576. selection of route. 316 

920. Financial value of trees. 547 

476, 489. Fineness of Portland cement.257, 264 

504. sand for mortar.273 

815. Fire clay curb.473 

956. First-class masonry. 562 

33. cost of pavements. 13 

1018. Flagging, specifications for.580 

776. Flagstone, specifications for.440 

Flint, specific gravity of (Table XXIV). 77 

weight of (Table XXIV). 77 

4o0d. Florida clay. 242 

96a. Flux for asphaltum. 44 

14, 524. Foothold, influence of.7, 297 

786. artificial stone for... 453 

778. Footpaths, asphalt for.440 

784. brick. . 451 

785. specifications for. 452 

782. compressed asphalt-tile. 450 

791, concrete for. 454 

795. specifications for. 458 

770. cross-slope of. 438 

768. definition of. 438 

775. dressing of stones for.439 

771. formation of. 439 

774. granite for. 439 

779. life of asphalt. 441 

773. materials employed for.. . 439 

833. price of.483 

787 of artificial stone. 453 

796. specifications for.458 

800. gravel.463 

797. tar concrete.462 

797. specifications for. 462 

772 qualities required .439 

d 09. removal of snow from. 542 



















































732 


INDEX. 


ARTICLE PAGE 

780, 781. Footpaths, specifications for asphalt.441, 442 

769. width of (Table LXXXII).422, 438 

777. wood for. 440 

527. Force required to sustain a vehicle upon an inclined road. 300 

1003. Forfeiture of contract. 574 

1030. Form of agreement. 592 

1039. bid or proposal. 591 

1031. bond. G01 

636. borrow-pits and spoil-banks. 338 

620. contour suitable for country roadways. 334 

620. street pavements. 334 

1027. contract. 586 

721. retaining-walls.402 

649. side-slopes.343 

687. tiles. 372 

48. traffic census. 19 

652. Formation, of embankments. 346 

948. specifications for. 559 

771. foot-paths.439 

801. the Central Park, N. Y., walks. 463 

862. Foreman, duties of. 499 

701. Formula for calculating area of water-way of culverts. 381 

730. thickness of retainiug-walls. 367 

1036. Forster’s crusher... 631 

452. Foundation, drainage of. 245 

452. essentials necessary to the forming of good. 245 

978. excavation, specifications for.569 

240. for asphalt pavements. 144 

316. brick pavements . 182 

771. footpaths. 439 

451. pavements. 245 

154. stone pavements. 88 

456. of blast-furnace slag. 246 

457. concrete. . . .247 

154. thickness of. 88 

726. retaining-walls. 407 

186. sand, and plank, defects of. 110 

455. manner of forming.246 

185. used for wood pavements. 110 

959. Fourth-class masonry. 563 

414, France, amount of material used to replace wear of broken-stone 

pavements. 220 

contnct work on roads. 517 

418, 865. cost of mainr.aining roads in.222, 504 

355. methods of testing the qualities of broken stone.202 

865. national loads of. 594 

road commissioners in. 514 ; 519 


















































INDEX. 


733 


ARTICLE PAGE 

France, road police in.519 

taxes in. 515 

task-work on roads in. 517 


866 . French system of highway maintenance, regulations for cautonniers 


(road laborers). 506 

914. Frequency of street sprinkling. 543 

521. Friction, resistance of. 295 

507. Frost, effect of, upon mortars. 277 

921. Fruit-trees and roads iu Saxony. 547 

330. Furnace slag for bricks. 187 

470. concrete. 253 

450a. paving.241 


G 


226. Gas, injurious effects of, on asphalt. 

106. tar. 

1036. Gates,crusher. 

153. Gauging of granite blocks. 

General stipulations applicable to all contracts. 

91a. Gilsonite. 

104. price of. 

Glass, specific gravity of (Table XXIY). 

weight of (Table XXIV)... 

65. Gneiss. 

specific gravity of (Table XXIV). 

weight of (Table XXIV). 

605. Grade on mountain roads. 

1033. Grader, New Era. 

671, 1033. Graders, mechanical. 

222-261. Grades, and asphalt pavements. 

steam-rollers. 

tractive power of horses. 

angles of. 

at street-intersections, adjustment of. 

definition of. 

determination of. 

effect of, upon the load drawn. 

estaolishing the. 

loads drdvvu by horses on. 

maximum. 

suitable for different paving materials 

methods of designating (Table LXII). 

minimum. 

of city streets (Table LXXX11)... 

on curves. 


399. 

595. 

596. 
7ol. 

594. 

595. 
53L 
609. 
532. 
599. 
601. 
608. 
606. 
745. 
585. 


... 139 
... 62 
. .. 631 
.... 87 
.... 570 
. .40, 42 
,... 61 
,. . . 77 

.... 77 
.... 27 
.... 77 

.... 77 
.... 328 
.... 618 
360, 616 
138, 152 
.... 214 
... . 326 
.... 326 
. ... 421 
.... 324 
.... 326 
.... 300 
.... 331 
.... 300 
.... 327 
.... 327 
.... 330 
.... 329 
414, 422 
.... 321 


/ 














































734 


INDEX. 


ARTICLE PAGE 

847. Grades, profit of eliminating. 489 

608. rise in feet per hundred. 330 

608. mile. 330 

540. steep, objections to. 303 

166. pavements on. 91 

752. transverse of street... 423 

607. undulating. 329 

947. Grading, definition of. 558 

947,1018. specifications for...558, 580 

1033. tools for. 605 

Grahamite (Table XI V«) .. 42 

63. Granite, abrasion of. 25 

64. absorptive power of (Table V). 26 

70. amount used for street purposes in 1889 (Table VII)..... 29 

443. block, artificial. 238 

140. pavement. 82 

142. advantages of. 82 

874. amount of dirt produced by.526 

894. area cleaned by one man.536 

877. cost of cleaning.527 

172. construction (Table XXVII). 97 

169. maintaining. 94 

143. defects of. 82 

170. manner of paying for. 94 

173. specifications for. 100 

171. blocks, area covered by one ton (Table XXVI). 97 

65. color of. 27 

816. curb, specifications for. 473 

65. description of. 27 

774. for footpaths. 439 

27. life of. 

masonry, weight of (Table XXIV). 77 

167. paving-blocks, durability of. 93 

153. gauging of. 87 

156. laying off. 88 

73. manufacture of. 30 

171. number of, to a square yard. 97 

157. ramming of. 89 

168. wear of. 93 

144. quality of. 84 

69. resistance to crushing of (Table VI). 28 

19. slipperiness of. 9 

69. specific gravity of (Table VI). 28 

72. uses of. 39 

70, 71. value of, used for street purposes in 1889 (Table VII). 29 

69. weight of (Table VI). 28 

650. Grass on slopes...,. 344 

















































INDEX. 


735 


ARTICLE PAGE 

1042. Gratings for catcli-basins. 676 

Gratuitous assistance to travellers. 511 

131. Gravel. 75 

639. and sand, shrinkage of. 339 

425. character of, for pavements. 229 

381, core for broken-stone pavements. 209 

800. footpaths. 463 

428. laying of .230 

424. pavements. 229 

432. cost of construction (Table XLIII). 231 

431. repair of. 230 

428. sprinkling of. 230 

transverse rise for (Table LXIY).334 

427. preparation of, for paving purposes. 229 

638. shrinkage of. 339 

427. size of, for paving. 229 

131. Tomkins Cove. 75 

131. analyses of. 76 

372, 461. voids in.206, 248 

812. walks, directions for their construction.470 

801. in Central Park, New York. 463 

433. weight of. 231 

with clay, specific gravity of (Table XXIV). 77 

weight of (Table XXIV). 77 

525. Gravity, effect of (Table LII). 298 

Greenstone, specific gravity of (Table XXIV). <7 

62. Grinding test. 25 

44. Gross cost of pavements . 13 

967. Grouting, specifications for. 565 

946. Grubbing, specifications for. 558 

1032. 'tools for... 304 

50. Guaranteeing pavements. 21 

738. Guard stones.410 

Gunpowder, specific gravity of (Table XXIV). 77 

weight of (Table XXIV).«. *7 

760, 826. Gutters. 428 ’ 478 

828. brick, specifications for.480 

827. cobblestone, specifications for. 479 

1042. -crossings of cast-iron. 378 

in Central Park, N. Y. 464 

694, on inclines, protection of. 3*7 

1018. specifications for. 582 

151 . stone block. 8,7 

329. -stones, specifications for.*« 4 $1 















































736 


INDEX. 


H 

ARTICLE PAGE 

676. Half-widths, calculating the. 364 

325. Hale pavement. 186 

583. Halting-places. 321 

323. Halwood paving-block..•. 185 

362, 1036. Hammers for breaking stone.205, 628 

361. Hand-broken stone. 204 

897, 1040. -brooms, kinds of.537, 662 

1040. -cart used by street patrol. 666 

362,1036. -hammers.205,628 

465. -made concrete. 250 

1038. -rammers, price of. 653 

892. sweeping.. 536 

89c. Hard bitumen. 38 

59, 352. Hardness of stones.'..24, 201 

1036. Harrisburg roller. 649 

673. Haul. 361 

322. Hayden paving-block. 184 

423. Heads of specifications for broken-stone pavements.. 227 

173. granite-block pavements. 100 

1027. repairing.‘. 585 

262. standard Trinidad asphalt pavement_ 153 

213. wood pavement. 124 

Heater for asphalt. 661 

211. Henson wood pavement. 121 

1016. Highway, specifications for construction of a. 578 

625. Hillside roads, form of transverse contour.. ... 336 

659. Hillsides, embankments on . 352 

659. retaining-walls on.'.352 

825. Hollow curbs of artificial stone.,. . 478 

370, 1036. Horse power required for stone-crushers. ... .206, 631 

397. rollers, defects of. 212 

1036. dimensions of. 646 

1036. price of .646 

work of, at different rates of speed (Table LYI). 302 

532. Horses, draught of . 300 

22. falls of, kinds and causes. Iff 

410, 1044. feet, effect of, on pavements.220, 683 

526. loads drawn by, on grades (Table LVII).302, 681 

maximum velocity unloaded (Table LIY). 301 

11, 12. number required to move one ton on different pavements 

(Table II). 6 

tractive power of, at different velocities (Table L1II). 301 

534. work done by. . 301 

1044. Horseshoes and pavements . 683 














































INDEX. 


rvo iv 

lo i 


ARTICLE PAGE 

78. Hudson River bluestone.. 32 

473. Hydraulic cement. 254 

472. lime. 253 

I 

Ice, specific gravity of (Table XXIV). 77 

weight of (Table XXIV). 77 

104. Imports of asphaltum into the United States in 1890. 61 

212. Improved wood pavements. 122 

834. Improvement of roads. 484 

842. Improvements, value of.488 

835. Improving clay roads. 485 

836. sand roads. 487 

850. the surface, profit of.491 

648. Inclinations given to side-slopes in different materials. 343 

699. of culverts. 381 

691. drains. 373 

527. Inclines, force required to sustain vehicles on.300 

536. loss of tractive power on. 302 

power required to haul one ton up different (Table LIX). . 304 

528. pressure of vehicles on... 300 

694. protection of gutters on . 377 

597. tractive power required in descending. 326 

491. Incompetent workmen, dismissal of. 571 

790. Increase in bulk of cement.454 

638. of excavated rock. 339 

766. Increasing width of carriageway at street-intersections.436 

1020. Indemnification for patent claims. 584 

1021. Indemnity bond. 584 

461-464. Ingredients for concrete, proportions of.248, 249 

1042. Inlet-traps for sewers. 676 

997. Inspectors. 572 

765. Instructions regarding street profiles. 434 

1028. to bidders. 587 

804 roadmen.502 

566. Instruments employed in reconnoitring. 311 

3. Interests affected in the selection of pavements. 2 

578. Intermediate towns.318 

085. Interpretation of specifications. 570 

152. Intersection, paving at street. 85 

450. Iron and wood, combinations of.241 

cast, crushing resistance of (Table XXIV). 77 

specific gravity of (Table XXIV). 77 

984 . specifications for. 570 

weight of (Table XXIV). 77 















































738 


INDEX. 


ARTICLE PAGE 

780. Iron curb. 443 

400. pavements. 241 

329. paving-bricks. 187 

708. pipe-culverts. 387 

weight of (Table LXXIII). 388 

1006. Iron pitch. 51 

161. Iron, slag, and Portland cement for joint-filliug. 90 

wrought, crushing resistance of (Table XXIV). 77 

specific gravity of (Table XXIV). 77 

983. specifications for.. 569 

weight of (Table XXIV). 77 

438. Italian trackways.... 236 

J 

442. Jasperite.237 

318. Joint-filling for brick pavements. 183 

159. stone blocks. 89 

192. wood pavements. 114 

161. of Portland cement and iron slag for pavements. 90 

191. Joints in wood paving, width of. 114 

706. of pipe-culverts. 383 

441. Junctions of track ways. 237 

152. paving at street.*. 85 

K 

Keeping tools in repair. 500-512 

682. Kinds of drainage... . 371 

79 Qa. Kosmocrete. 431 

188. Kyauiziug. 112 

L 

881. Laborers’ wages in Baltimore. 531 

878. Berlin. 537 

879. Paris..... 530 

100, lOOp. Lake pitch. 50-56 

100. 100«, 100 /?. Land pitch..50, 51. 56 

616. Land, width of, appropriated for road purposes. 332 

384. Layers of broken stone, thickness of . 210 

965. Laying masonry in freezing weather, specifications for. 564 

466. of concrete. . 250 

156. granite blocks. 

428. the gravel. 230 









































INDEX. 


739 


ARTICLE PAGE 

Lead, resistance to crushing of (Table XXIV). 77 

specific gravity of (Table XXIV). 77 

weight of (Table XXIV). 77 

837. Leaves on sandy roads. 469 

645. Length and angle of slopes (Table LXVI). 341 

849. decreasing the, profit of. 490 

932. of culverts, to ascertain. . 551 

level road equivalent to an inclined road (Table LIX).... 304 

148. paving-blocks. 85 

687. tiles. 372 

608. Level stretches. 330 

572. Levels. 312 

779. Life of asphalt footpaths. 441 

27. pavements... 11 

27. brick pavements. 11 

27, 167. granite-block pavements. 11, 93 

27. limestone-block pavements. 11 

444. plank roads. 238 

27. sandstone pavements. 11 

27, 193. wood pavements.11, 115 

85. Ligonier. 36 

472. Lime, common. 253 

472. hydraulic. 253 

specific gravity of (Table XXIV). 77 

weight of (Table XXIV). 77 

63. Limestone, abrasion of. 25 

64. absorptive power of (Table V). 26 

amount produced for street purposes in the United States 

in 1889 (Table XIII). ... 36 

996. bituminous.43, 49 

99$. analysis of. 50 

99/. bow used. 49 

27. block pavements, life of. 11 

82. description of. 34 

84, 165. paving, experience with.35, 91 

resistance to crushing of (Table XII). 36 

specific gravity of (Table XII). 36 

83. uses of. 35 

value of, used for street purposes in 1889 (Table XIII).. 36 
weight, of (Table XII). 36 

Limestones, bituminous, specific gravity of (Table XXIV). 77 

Liquid bitumen. 45 

specific gravity of (Table XXIV). 77 

weight of. 77 

992. Liquors, spirituous. 571 

93c, 99c. Lithocarbon.42, 49 

715. Live loads and bridges. 396 
















































740 


INDEX. 


ARTICLE PAGE 

31. Liverpool pavements. 1£ 

400. Loaded vehicles, pressure of. 214 

536. Loads drawn by horses on grades (Table LVII).302, 681 

439. moved on trackways. 237 

639. Loam, shrinkage of. 339 

592. Location final. 324 

555. of country roads. 309 

447. Log roads. 240 

880. London, pavements.530 

880. street cleaning in. 530 

858. Loose stones on roads.496, 509 

669. Loosening earth.360 

671. by machinery. 360 

1009. Loss and damage. 576 

581. of height. 320 

536. tractive power on inclines. 302 

M 

434. Macadam, bituminous. 231 

345. concrete. 199 

343. pavements. 198 

345. analyses of. 199 

1037. roads, tools employed for maintenance of. 653 

1018. Macadamizing, specifications for.. 580 

1036. tools for.628 

345. MacAdam’s method, defects of. 199 

364. Machine-broken stones, objections to. 205 

492. for testing cement.266 

511. -mixing of mortar and concretes vs. hand-mixing.284 

Machines for mixing concrete, price of.660 

418. Maintenance, broken-stone pavements, cost of. 221 

36. considerations concerning. 14 

860. cost of.498 

285. asphalt and coal-tar pavements. 169 

852. definition of. 493 

853. necessity of. 49 ft 

265. of asphalt pavements by contract. 159 

233. cost of . 141 

836. clay roads. 486 

857. country roads. 494 

341. earth roads, cost of. 488 

169. granite-block pavements, cost of... 94 

macadam roads, tools employed for. 628 

403. steam-rollers, cost of. 215 

865. the French roads. 504 














































INDEX. 


741 


ARTICLE PAGE 

206. Maintenance, of wood pavements, cost of. 120 

214. by contract.128 

856. systems of.494 

88a, 93d, 96d, 98a. Maltha.38, 42, 45, 48 

1025. Manhole covers, etc., alteration of. ... 585 

405. Manner of applying the roller.217 

318. laying brick pavements. 183 

170. paying for granite block pavements. 94 

415. restoring the thickness of broken-stone pavements. 220 

73. Manufacture of granite paving-blocks. 30 

114. paving-brick. 65 

570. Map. 312 

647. Marshes, embankments across.349 

956. Masonry, first-class. 562 

959. fourth-class. 563 

965. layiug, in freezing weather, specifications for.564 

957. second class. : . 562 

956. specifications for.562 

958. third-class. 563 

weight of (Table XXIY). 77 

Materials employed for footpaths.439 

for bridges. 397 

culverts. 382 

embankments. 346 

old, disposal of. 584 

paving, selection of. 24 

quality of, specifications for. 571 

samples of.571 

Maximum grade.327 

adopted by Telford. 327 

the French eugineers. 327 

of streets in various cities.420 

on mountain roads.328 

to determine . 328 

Measurement of earth-work. 560 

overhaul.572 

pavements. 573 

work... 573 

Mechanical graders...361, 616 

price of. 616 

. 536 


773. 

718. 

705. 

652. 

1023. 

58. 

993. 

994. 
592. 
602. 
602. 
749. 
605. 
604. 
949. 
999. 
999. 
999. 
671. 

1033. 

895. 

896. 


sweepers. 

cost of operating. 537 

price of..». 663 

162. Medina sandstone. . 91 

905. Melting snow, cost of.539 

571. Memoir. 

209. Mesquite-block pavements. . 


312 

95 





















































742 


INDEX. 


ARTICLE PAGE 

362. Method of breaking stones by band. 204 

875. cleaning streets. 526 

682. Methods employed for draining... 371 

61. testing durability. 25 

Mexican asphaltum (Table XIVa). 42 

Mica, specific gravity of (Table XXIV). 77 

weight of (Table XXIV). 77 

89£>. Mineral caoutchouc. 38 

91, 93 Mineral pitch.40, 41 

88 a, 94. tar. .38, 42-43 

606. Minimum grade. 329 

722. thickness of retaiuing-walls . 402 

613. width of roads. 332 

1010. Miscellaneous work, specifications for. 576 

686 . Mitre-drains. 371 

465. Mixing concrete . 250- 

343. Modern macadam pavements. 198 

342. Telford “ .. 198 

647. Moisture, effects of, on earth. 342' 

56. Money wasted in opening pavements. 23 

763. Monuments. 431 

64. Mortar, absorptive power of (Table V). 26 

500. adhesive strength of (Table XLV). 270- 

484. amount of water required for. 261 

495. characteristics of. 268 

494. composition of.. 268 

502. compressive strength of. 273 

505. effect of age on strength of. 276 

507. frost upon. . 277 

504. size of grain of sand on strength of (Table 

XLVIII). 276 

471. for con Crete.253 

506. permeability of. 276 

496. quality of sand for. 268 

497. water for... 269' 

501. shearing strength of (Table XLVI). 272 

specific gravity of (Table XXIV). 77 

976. specifications for. 568 

499. strength of . 270 

503. tensile strength of (Table XLVII). 273 

weight of (Table XXIV) . 77 

557. Motive power, economy of. 309 

579. Mountain roads... 320 

605. grade on. 328 

582. water on. 321 

617. width of . 333 

872. Mud, composition of (Table LXXXV). 523, 

















































INDEX. 


743 


ARTICLE PAGE 

Mud, specific gravity of (Table XXIV) . 77 

weight of (Table XXIY). 77 

N 

78. Names, commercial, of sandstone. 33 

88 a, 91. Naphtha. 38-40 

specific gravity of (Table XXIV). 77 

weight of (Table XXIV). 77 

544. Narrow tires.305, 306 

865. National roads of France. 504 

473. Natural Portland cement. 254 

645. slopes of earth (Table LXV). 341 

390. Necessity of binding. 211 

853. maintenance. 493 

886 . New York, street-cleaning in. 533 

Nitro glycerine. 367 

43. Noisy pavements, objections to. 16 

93. Nomenclature of asphaltum. 41 

817. Nomination of caulonniers.. 507 

1004. Non-completion, damages for. 575 

989. Notice to contractors. 570 

Number of cubic yards of broken stone required for different 

widths (Table XL).. 210 

171. granite blocks to a square yard (Table XXVI). 97 

11 . horses required to move one ton on different pavements 6 

183. wood blocks to a square yard. 109 

O 

1 . Object of pavements. . 1 

618. raising the centre of roads. 334 

222. Objections to asphalt pavements. 137 

137 . Belgian-block pavements. 81 

134 . cobblestone pavements. 79 

588. crookedness. 323 

43 . dusty pavements. 16 

143 granite block pavements. 82 

397 . horse rollers. 213 

347 . Macadam pavements... 199 

364. machine-broken stones...205 

43 . noisy pavements. 16 

540 . steep grades. 303 

344 Telford pavements. 198 

395 traffic consolidation..... 212 








































744 


INDEX. 


ARTICLE PAGE 

695. Objections to water-breaks. 677 

179. wood pavements. 105 

591. zigzags. 323 

17. Observations in Loudon on slipperiness of pavements. 8 

16. United States on slipperiuess of pavements. 8 

92. Occurrence of aspkaltum.. 40 

952. Off-take ditches, specifications for... 561 

435. Old asphalt and broken stone.«. 232 

1023. materials, disposal of. 584 

986. Omissions in specifications. 570 

368. Operating stone-crushers, cost of., .205 

403. steam-rollers, cost of. 215 

38. Opinions, prevailing, concerning pavements. 15 

862. Organization of road force.. . .. 499 

862. accounts. 498 

862. county engineer... 498 

862. chief foreman... 501 

862. foremen.. 501 

862. number of men required. 499 

862. roller.500 

862. snow. 501 

862. storage and delivery of broken stone_ 501 

862. team labor and materials. 500 

862. tools. 500 

91. Origin of bitumen. 49 

687. Outlets, drain, protection of. 372 

673, 999. Overhaul, how measured.361, 572 


P 


0 

735. Parapets.. 409 

735. height of . 409 

964. specifications for. 564 

735. thickness of.409 

879. Paris, street-cleaning in.530 

1000. Partial payments. 573 

1020. Patent claims, indemnification for. 584 

880. Patrol system iu London.. 530 

29. Pavement, the cheapest. 11 

9. Pavements, adaptability of. 4 

874. amount of dirt produced by different... 526 

1044. and horseshoes.683 

10 . and popular prejudice. 5 

450 f, 786. artificial stone.243-453 

136. Belgian block. 81 

306. brick. 179 













































INDEX. 745 


ARTICLE PAGE 

335. Pavements, broken-stone. 195 

346. advantages of... .. 199 

396. rolling. 219 

393. compacting the stone.219 

393. by rollers drawn by horses_211 

393. by steam-rollers. 213 

393. the traffic. 212 

347. defects of.,. 199 

380. failure of thin. «... 210 

421. in Bridgeport, Conn.229 

420. Chicago. 222 

419. England. 222 

413. loss of thickness average annual. 212 

417. recoating when it should be done.222 

423. specifications for.222 

383. spreading the stone. 209 

378. thickness of. 208 

384. the layers. 210 

409. wear of. 219 

39. care of. 14 

40. cleansing of. 15 

133. cobblestone. ... 79 

comparative merit of (Table IV). 21 

28. considerations concerning cost of. 11 

10. desirability of. . .*. 5 

55 . destruction of. 22 

23. durability of. 10 

32. economic benefit of good. 13 

410. effect of atmospheric changes on . 220 

451. foundations. 245 

460. character of concrete for. 248 

457 . concrete for. 247 

142. granite-block. 82 

44 . gross cost of. 16 

50. guaranteeing. 21 

325. Hale brick . 186 

325. Hale system. 186 

323. Hal wood system. 185 

322. Hayden system. 184 

211. Henson’s system. 121 

3 . interests affected in the selection of. 2 

load drawn by a horse on different (Table LVII). 302 

345 . macadam, analyses of. 199 

9 9 . measurement of. 573 

1 . object of.... • • • 1 

292. of asphalt block. 173 

208. cedar blocks. 121 


















































746 


INDEX. 


ARTICLE PAGE 

281. Pavements of coal-tar. 168 

282. and asphalt... 168 

424. gravel. 229 

432. cost of construction. 231 

450. iron.. 241 

31. Liverpool. 11 

209. mesquite-block. 121 

166. on steep grades. 91 

451. permanence of...,. 245 

2 . qualities of good. 1 

34. relative economies of. 14 

15. safety of.... 7 

454. sand as a foundation for. 246 

14. serviceability of...., . 7 

451. stability of. 245 

280. vulcauite.,. 167 

56. waste of money in opening. 23 

152. Paving at street-junctions. 85 

148, blocks, length of. 85 

73. makers, wages of. 31 

73. manufacture of granite. 30 

71. price of. 29 

146. shape of. 84 

146. size of. 84 

147. width of. 84 

63. brick, abrasion of. 25 

64, 119. absorptive power of (Table V).26, 67, 68 

117. characteristics of good. 66 

111 . clay for . 64 

114. manufacture of. 64 

prices of (Table XXI) . 68 

119. resistance to crushing of (Table XXIY) .. .67, 68 , 69, 77 

size of. 68 

119. specific gravity of (Table XXI).67, 77 

119. weight of (Table XXI). 68 

58. material, selection of. 24 

106. pitch. 62 

1005 Payment of claims. 575 

1013. workmen. 577 

1000 Payments, partial. 573 

1015. when made.'. 577 

Peat, weight of (Table XXIV). 78 

421. Permanence of pavements. 245 

506. Permeability of mortars. 277 

Peruvian asphaltum (Table XIVa). 42 

519. Penetration, resistance of. 290 

8 8a, 91. Petroleum. 38, 40 

















































INDEX. 


747 


976. Petroleum, residuum. 46 

97d. specification for. 47 

976. test for. 46 

specific gravity of (Table XXIV). 77 

weight of (Table XXIV). 77 

90 90a. Petroleue. 39 

133. Philadelphia, cobblestone pavements in. 79 • 

887. street-cleauiug in. 533 

415. Picks on steam-rollers, objectionable.220 

981. Piles, specifications for. 569 

706. Pipe-culverts. 383 

971. specifications for. 566 

iron, dimensions, weight, and price of (Table LXXIII).388 

70. vitrified, dimensions, weight, and price of (Table LXXI) .... 387 

Pipes, discharging capacity of (Table LXXVIII). 395 

433. Pit-gravel, weight of...:...231 

88a, 93. Pitch, mineral. 38-41 

106. paving. 62 

specific gravity of (Table XXIV). 77 

weight of. 77 

656. Plains, embankments over. 349 

186. Plank-and-sand foundation, defects of.. .. 110 

444. roads. 288 

445. construction of . 238 

446. cost of...... !*. 240 

446. life of . . .. 240 

995. Plans and specifications, deviations from. 571 

1033. Ploughs, cost of operating . 605 

1033. for grading, price of.605 

1033. quantity of material loosened with. 605 

966. Pointing, specifications for. . 565 

59. Porosity of paving materials. 24 

Porphyry, specific gravity of (Table XXIV). 77 

weight of (Table XXIV). 77 

1035. Portable boilers, price of.. .•. 627 

1036. engines, price of... 641, 642 

475. Portland cement. 256 

476. characteristics of. 257 

476. contraction of. 258 

509. English, specifications for. 283 

476. expansion of . 258 

467, 484. fineness of.-.. 257-261 

475. 476. specific gravity of. 256, 257 

973. specifications for. 386 

476. tensile strength of. 258 

477 . tests for.258 

476, 501. weight of. 257-272 



















































748 


INDEX. 


ARTICLE PAGE 

10. Popular prejudice aud pavements. 5 

518. Power required to draw wheels over obstacles. 289 

haul one ton up different inclines (Table LIX).. 304 

1008. to suspend work. 576 

99/, 266. Preparation of the bituminous limestone. 49, 162 

99g. bituminous sandstones. 50 

424. gravel for paving. 229 

516. roadbed, specifications for ..288 

100<?. Trinidad asphaltum. 52 

990. Preservation of engineer’s marks. 571 

188. wood. Ill 

Pressed brick, resistance to crushing of (Table XXIV). 77 

specific gravity of. 77 

weight of. 77 

400. Pressure of loaded vehicles. 214 

397. rollers. 213 

528. vehicles on inclines . 300 


38. Prevailing opinions concerning pavements 
1014. Prices in contract. 


104. 

161. 

104. 

833. 

104. 

71. 

1033. 


129. 


of asphaltum in New York in 1893 

bituminous cement. 

California bituminous rock. 

foot walk materials.. 

gilsonite. 

granite blocks.. , 

mechanical graders. 

paving-brick (Table XXI). 

sand . . 


367, 368. stone-crushers. 

1040. tools for cleaning. 

1032. clearing.. 

1033. grading. 

1032. grubbing. 

1036. macadamizing. 

1037. maintenance . 

675. Prismoidal formula.. 


. 12 
. 577 
. 61 
. 90 
. 61 
. 483 
. 61 
. 29 
. 616 
. 68 
. 75 
. 205 
. 662 
. 604 
. 605 
. 604 
. 628 
. 653 
. 363 


8 . Problem involved in the selection of pavements. 4 

104. Production of bituminous rock in the United States in 1893 (Table 


XVIII). 90 

bluestone in the United States in 1889 (Table XI)... . 34 

granite in the United States in 1889 (Table VII)_ 29 

limestone in the United States (Table XIII). 86 

sandstone for street purposes in 1889 (Table X). 34 

574. Profile. 315 


593. construction. 324 

765. Profiles, street. 434 

849. Profit of decreasing the length... 490 














































IS 1)EX. 


749 


ARTICLE PAGE, 

847. Profit ot eliminating unnecessary grades. 489 

850. improving the surface. 491 

1003. Progress of work. 574 

389. Properties of binding adopted by the French engineers. 211 

100. Trinidad asp halt tun. 49 

420. Proportion of clay to gravel. .229 

716. Proportioning of bridges. 396 

461, 462. Proportions of ingredients for concrete. 248 

464. usual for concrete. 249 

253. materials used in the manufacture of Trinidad 

asphalt pavements. 160 

724. retaining-walls. .402 

1029. Proposal, form of... . 591 

689. Protection of drain-outlets. 373 

694. gutters on inclines. 377 

1006. persons and property. 575 

734. roads.408 

927. trees. 549 

31.. Public bodies and economy. 12 


Q 


314. Quality of bricks. 

830. cross stones. 

776. flagstones. 

144. granite.. 

425. gravel for roads. 

993. materials. 

459. materials for concrete. 

495. mortar. 

126. sand. 


182 

481 

440 

84 

229 

571 

248 

268 


155. for cusliion-coat... 88 

349 , 351. stone for broken-stone pavements. 200 , 201 

459. concrete.247 

497. watei for mortar. 269 

187. wood for paving.'. Ill 

2. Qualities of good pavements. 1 

780. required in footpaths . 441 

382. Quantity of broken stone required per mile for different widths 

(Table LX). 209 

1033. material loosened with ploughs.. 605 

464. materials required for one cubic yard of concrete .... 249 

128. sand required for bedding-blocks... 75 

836. stone broken by hand . 205 

367, 1036. machines...205-634 

463. watei required for concrete. 249 













































750 


INDEX. 


ARTICLE PAGE 

498. Quantity of water required for mortar. 299 

913. street-sprinkliug. 543 

371. Quarrying stone, cost of (Table XXX).206 

Quartz, weight of (Table XXIV). 77 

specific gravity of (Table XXIY). 77 

67. Quartzite. 28 

487. Quick- and slow-setting cements, definition of.263 

R 

1033. Rails, weight of .. 614 

19. Rain and asphalt pavement. 9 

699. Rainfall, amount of. 380 

466. Rammers for concrete, dimensions of. 250 

1038. hand, price of.. 654 

1038. weight of. 654 

466. Ramming, amount required for concrete. 250 

466. concrete.. 250 

158. granite blocks... 89 

897. Rattan brooms. 537 

61. Rattler tests. 25 

417. Recoatiug broken-stone pavements, when it should be done. 221 

558. Reconnoissance. 309 

834. Reconstruction of roads. 485 

863. Records. 502 

189. Rectangular wood blocks. 113 

95. Refined asphaltum . 43 

lOOw. specific gravity of. 55 

751. Refuges at street-intersections.421 

891. Refuse, amount collected from streets. 525 

899. disposal of (Table LXXXVI)...537 

866. Regulations for cantonniers. 506 

34. Relative economies of pavements. 14 

832. Relaying bridge-stones, specifications for. 483 

900. Removal of snow. 538 

907. from footpaths. 540 

902. in Milan. 538 

861. Repair of broken-stone pavements. 498 

431. gravel pavements. 222 

1024. Repairs, security retained for. .585 

1026. Repaying, specifications for. 585 

862. Requisitions for tools, etc. 498 

521. Resistance of friction. 295 

525. gravity (Table LII). 298 

519. penetration. 290 

to crushing of basalt (Table XXIY). 77 















































INDEX. 751 


ARTICLE PAGE 

Resistance to crushing of bluestone (Table IX). 34 

bricks (Table XXIV). 77 

cast-iron (Table XXIV). 77 

chalk (Table XXIV). 77 

common hard brick (Table XXIV). 77 

concrete (Table XXIV). 77 

69. granite (Table VI). 28 

lead (Table XXIV). 77 

85. Ligonier “granite”. 36 

limestones (Table XII). 35 

119. paving-bricks....67, 69, 77 

pressed bricks (Table XXIV). 77 

81. sandstones (Table IX). 33 

soft brick (Table XXIV). 77 

steel (Table XXIV). 78 

Stourbridge brick (Table XXIV). 77 

87. trap-rocks (Table XIV). 37 

wood (Table XXII). 73 

wrought-iron (Table XXIV)... 77 

517. to traction. 289 

on different road surfaces (Table L) . 295 

721. Retaining-walls. 402 

729. and springs. 407 

726. dry-stone. 406 

727. failure of. 407 

725. form of. 406 

730. formula for thickness of. 407 

726. foundation of.407 

730. mimimum thickness of. 407 

659. on hillsides. 352 

724. proportions of. 402 

954 . specifications for.561 

733 . where they should be built. 408 

90, 90 a. Retine.39-40 

1036. Revolving stone screens, price of. 640 

996. Right reserved to alter details. 571 

1636. Ring gauge. *. 689 

953. Rip-rap, specifications for.561 

Rise, amount of transverse (Table LXIV). 834 

739. River-banks, roads along.410 

862. Road force, organization of. 498 

1033. -leveller, price of... 620 

1033. use of. 620 

1033. machines, price of. 616 

•surface, resistance to traction on different (Table L).295 

1036. Roadbed roller, form of. 629 

1036. price of. 629 




















































752 


INDEX. 


ARTICLE PAGE 

1036. Roadbed roller, weight of. 629 

516. specifications for preparation of..... 288 

864. Roadmen, instructions to. . • • 502 

862. number required.*. 498 

584. Roads, alignment of. 321 

739. along river-banks . 410' 

739. the seashore . 410' 

448. charcoal.240- 

835. clay. 485 

447. corduroy. 240 

555. country, location of. 309 

846. defects of existing. 489 

682, 693. drainage of.371-375 

865. French, maintenance of. 504 

424. gravel. 229 

447. log. 240 

865. national, of France. 504 

number of acres required per mile for different widths of 

(Table LXI1I). 333 

444. plank . 238 

734. protection of.408 

834. reconstruction of. 485 

837. sand.487 

625. transverse contour. 336 

919. trees on. 546 

611. width of. 332 

660. Roadways on rock-slopes. 354 

618. transverse contour of. 334 

661. Rock-cliffs, manner of forming roads along. 355 

662. excavations.357 

664. cost of... 359 

1035. tools for. 622 

639. increase in bulk of.•...339 

662. quantity of, loosened by blasting. .. 357 

660. slopes, roadways on. 354 

86. Rocks, trap. 36 

394. Rollers, horse, defects of. 212 

1036. dimensions of . 646 

1036. price of.646 

397. pressure of... 213 

396. steam, advantages of... 213 

401. area rolled per day. 215 

1036. dimensions of... 650 

405. manner of applying.217 

301. speed of. 215 

404 Rolling, amount required for broken-stone pavements. 216 

406. cost of.. 217 

















































INDEX. 


753 


ARTICLE 

453. Rolling, foundations.. 

520. resistance of wheels... 

Roman cement, specific gravity of (Table XXIV)... 

weight of (Table XXIV). 

473. Rosendale cement. 

973. specifications for .. 

tests for. 

973. weight of (Table XXIV). 

26. Roughness and durability. 

182. Round wood blocks. 

576. Route, principles to be observed in final selection of 


PAGE 

245 

294 

77 

77 

254: 

567 

567 

255 

11 

109 

315 


S 


15. 

907. 

994. 

123. 

639. 

454. 

126. 

381. 

475. 

504. 

127. 
155. 
504. 

453. 

454. 
496. 
223. 

129. 
126, 

128. 

837. 

837. 

125. 

123. 
504. 

974. 

126. 

124. 
127, 

130. 


Safety of pavements. 7 

Salt used for the removal of snow. 540' 

Samples of materials. 571 

Sand. 74 

and gravel, shrinkage of. 339 

as a foundation for pavements. 245 

cleanness of.*. 75 

core for broken-stone pavements.209 

effect of, on Portland cement. 255 

size of grain on strength of mortar (Table XLVIII).. 276 

for concrete.i. 75 

cushion-coat of stone blocks. 88 

mortar, fineness of. 273 

foundations, defects of .. 245 

manner of forming. 246 

in mortar. 268 

injurious effects of, on asphalt pavement. 138 

price of . 75 

488. quality of. 7c* 

quantity required for bedding block. 75 

road, load drawn by a horse on (Table LV1I). . 80S 

roads, improving of..487 

trees of..... 487 

sharpness of. 75 

size of, for paving purposes. 74 

sieves for sifting (Table XLXI). 276 

specific gravity of (Table XXIV) . 78 

specifications for. 567 

to test.*. 75 

use of. .. * - 74 

462. voids in.75,^ 248 

weight of (Table XXIV).*.... • • • '75, <8 













































754 


INDEX. 


ARTICLE PAGE 

127. Sand with clay. 75 

64. Sandstone, absorptive power of (Table V). 26 

79. amount produced for street purposes in 1889. 34 

analyses of (Table VIII). 32 

99y. bituminous, in America. 50 

99^. Europe . 50 

102. analysis of. 58 

99</. preparation of. 50 

164, 172. block pavements, cost of construction.91, 97 

79. commercial names of. 33 

74. description of. 31 

27. pavements, life of. 11 

81. resistance to crushing of (Table IX) . 33 

81. specific gravity of (Table IX) . 33 

79. value of, used for street purposes in 1889 (Table X)- 34 

weight of (Table IX). 33 

182. Sapless cedar blocks. 109 

1040. Scoop used by street patrol. 667 

670, 1033. Scrapers. 360-607 

982, 1033. capacity of. 607 

1033. cost of.607 

1040. scraping-machines. 665 

838. improper use of.;. 487 

839. on earth roads.. 487 

350, 387. Screening the broken stone ..200. 211 

739. Seashore, roads along. 410 

916. water for street sprinkling .,. 544 

957. Second-class masonry... 562 

1024. Security retained for repairs... 585 

575. Selection of bridge sites.;. 315 

3. pavements, interests affected in the. 2 

58. paving-material... 24 

922. trees. 547 

Serpentine, specific gravity of (Table XXIV).. 77 

weight of (Table XXIV).. 77 

41. Service of pavements, cost of. 15 

14. Serviceability of pavements. 7 

821. Setting curb, specifications for. 475 

476. of Portland cement.. 258 

937. stakes for curb. 555 

640. Settlement of earth. 339 

1041. Sewer inlet-traps. 677 

1022. Sewers, right to construct. 584 

Shales, specific gravity of (Table XXIV). 77 

weight of (Table XXIV). 77 

313. Shape of bricks. 182 

357. stone for broken-stone pavements. 204 

















































INDEX. 


r*-' ~ ~ 

7do 


-ARTICLE PAGE 

146. Shape of stone paving-blocks. . 84 

182. wood paving-blocks. 109 

125. Sharpness of sand. 75 

503. Shearing streugth of mortar (Table XLVI). 273 

132. Shingle. 76 

specific gravity of (Table XXIV). 78 

weight of (Table XXIV). 78 

670, 1033. Shovels.360, 605 

639. Shrinkage of clay. 339 

639. earth. 339 

639. gravel. 339 

639. and sand. 339 

639. loam. 339 

639. vegetable soil. 339 

692. Side ditches .. T..375 

649. form of. 339 

648, 650. Side ditches, inclination of. 339 

654. - of embaukments.*. 348 

930. staking out... 550 

Sidewalks, average width of, in various cities (Table LXXIII).422 

504. Sieves, size of, for sifting sand (Table XLIX).276 

686. Silicious soils, drainage of. 371 

687. Silt basins. 372 

Sinking fund that with compound interest will amount to $1 at the 

end of a term of years (Table XC). 689 

67. Sioux Falls stone. 28 

313. Size of bricks. 182 

131. gravel for paving. 75 

123. sand tor paving purposes..... 74 

504. sieves for testing sand (Table XLIX). 276 

367, 368. stone-crushers .205-634 

357. for broken-stone pavements. 204 

459. concrete. 248 

146. paving-blocks. 84 

182. wood paving-blocks. 109 

549. wheels.307 

4506. Slag-blocks. 259 

Slate, specific gravity of (Table XXIV). 78 

weight of (Table XXIV). 18 

19. Slipperiuess of asphalt. 9 

21. and wood, cure for. 10 

19. granite. 9 

19. wood. 0 

651. Slips . 344 

645. Slope, angles and length of ^Table LXVI).. • • 341 

788. of footpaths. 453 

954. -walls, specifications for. 561 



















































756 


INDEX. 


ARTICLE 

650. Slopes, covering of. 

651. drainage of. 

natural, of earth (Table LXV). 

654. of embankments.. 

946. Sloping ground, specifications tor preparation of 

487. Slow-setting cement. 

1036. Smith’s hydraulic crusher. 

13. Smoothness, economy of. 

906. Snow, disposal of.= . 

-ploughs, form of. 


900. 

removal of. 

903. 

cost of. 

907. 

from footpaths 

902. 

in Milan. 

908. 

weight of (Table XXIV).. 


Soapstone, specific gravity of (Table XXIV). 

weight of (Table XXIV). 

Soft interior brick, resistance to crushiug of (Table XXIV).. 

specific gravity of (Table XXIV). 

weight of (Table XXIV). 

453. Soils, natural character of. ... 

100. Source of Trinidad asphalt-urn.. 

470. Specific gravity of American natural cements. 

89c. asphaltum. .. 

basalt (Table XXIV). 

bluestoue (Table IX). 

brick masonry (Table XXIV). 

cast-iron (Table XXIV). 

chalk (Table XXIV). 

clay (Table XXIV). 

with gravel (Table XXIV). 

common hard brick (Table XXIV). 

460. concrete (Table XXIV). 

crude asphaltum. 

eaith (Table XXIV). 

English Portland cement (Table XXiV).. 

feldspar (Table XXIV). 

Hint (Table XXIV)... 

glass (Table XXIV) . 

gneiss (Table XXIV). 

69. granite (Table VI). 

gravel with clay (Table XXIV).. 

greenstone (Table XXIV). 

gunpowder (Table XXIV). 

ice (Table *XXIV). 

lead (Table XXIV). 

lime (Table XXIV).. 


PAGE 

... 344 
... 346 
.... 341 
... 341 
... 559 
.. . 263 
.. 632 

... 6 
... 540 
... 673 
... 538 
... 539 
... 540 
... 538 
77, 541 
... 78 

... 78 

... 77 

... 77 

... 77 

... 245 
... 50 

... 254 
. 39, 77 
.. 77 

... 34 

... 77 

... 77 
... 77 
... 77 
... 77 

... 77 
77, 248 
. .39-52 
... 77 
.. . 77 
... 77 
... 77 

... 77 

... 77 


77 

77 

77 

77 

77 

77 


















































INDEX. 


757 


ARTICLE PAGE 

Specific gravity of limestone (Table XXII). 35 

liquid bitumen (Table XXIV). 77 

mica (Table XXIV). 77 

mortar (Table XXIY). 77 

mud (Table XXIV). 77 

naphtha (Table XXIV). 77 

119. paving-brick (Table XXIV).67, 77 

petroleum (Table XXIV). 77 

pitch (Table XXIV). 78 

porphyry (Table XXIV). 78 

472, 473. Portland cement (Table XXIV).77, 258 

pressed brick (Table XXIV). 77 

quartz (Table XXIV). . 78 

refined asphaltum. 39 

refined Trinidad asphaltum. 55 

Roman cement (Table XXIV). 77 

sand (Table XXIV). 78 

81. sandstones (Table IX). 33 

serpentine (Table XXIV). 78 

shales (Table XXIV). 78 

shingle (Table XXIV) .. 78 

slate (Table XXIV). 78 

soapstone (Table XXIV). 78 

soft inferior brick (Table XXIV). 77 

steel (Table XXIV). 78 

Stourbridge fire-brick (Table XXIV). 77 

trap-rocks (Table XIV). 37 

Trinidad asphaltum.39-55 

water (Table XXIV). 78 

wood (Table XXII). 73 

wrought-irou (Table XXIV). 77 

943. Specifications, definition of. 558 

995 . deviation from. 571 

509. (English) for Portland cement. 283 

1017. for a bulkhead. 579 

960,961. arch culverts...563, 564 

822. artificial curb and gutter. 476 

979 foundations. 569 

786 ’ stone footpaths. 458 

pavements. 244 

296. asphalt-block pavements. 175 

780, 781. footpaths.. .441-443 

203 pavement on bitumiuous base. 158 

204 hydraulic concrete base.... 159 

138 . Belgian-block pavements.. 81 

303 . bituminous-rock pavements. 177 

818. bluestone curb. 474 


















































758 


INDEX. 


ARTICLE PAGET- 

954. Specifications for breast-walls. 561 

828. brick gutters. 480 

831-334. pavements.187-193 

784. footpaths...452 

968. masonry.565 

830. bridge-stones.481-483 

715. bridges.402 

423. broken-stone pavements.227 

984. cast-iron. 570 

291. coal-tar and asphalt pavements. 170 

1018. catch-basins. 583 

696. water-ditches. 561 

972. cement.. 567 

962. centring...,. 564 

944. clearing . 538 

1011 . cleaning up. 57 ? 

945. close cutting. 558 

135. cobblestone pavements. 79 

982. cofferdams. 569 

782. compressed-asphalt-tile footway-pavement. 450 

795. concrete footpaths. 458 

512-516, 977. concretes.285-8-568 

830. crossing-stones.481 

960. culverts. 563 

1018. curbing. 580 

950. drains.561 

823. dressing old curb.478 

970. dry box-culverts. 5(56 

969. walls... 565 

948. embankments . 55 !) 

1018. flagging. 580 

776. flagstones. 440 

743. fencing . 413 

978. foundation excavation.569 

947. grading. 558 

173. granite-block pavements. 100 

816. curb. 473 

967. grouting. 565 

946. grubbing.. 

829. gutter-stones. 481 

828. gutters . 480 

450</. hydraulic-cement, pavement.,. 244 

827. laying cobblestone gutters . 479 

965. masonry in freezing weather. 564 

1018. macadamizing... . 530 

956. masonry . 502 

1010. miscellaneous w r ork. 576 


















































INDEX. 759 


article . . page 

976. Specifications for mortars. 508 

962. off-take ditches. 561 

964. parapets. 564 

97<?. petroleum residuum. 47 

981- piles. 569 

971. pipe-culverts. 566 

966. pointing. 565 

616. preparation of roadbed. 288 

946. sloping ground. 559 

927. protection of trees. 549 

993. quality of materials. 571 

837. relaying crossing-stones.483 

1026. repaving.585 

824. resetting curb.478 

954. retaining-walls. 561 

953. rip-rap. 561 

974. sand.567 

820. setting curb.475 

954. slope walls. 561 

262. Standard Trinidad asphalt pavements. 153 

1027. street cleaning. 586 

797. tar-concrete footpaths.462 

339, 422. Telford’s pavement.196-224 

980. timber. 569 

1016. the construction of a highway. 578 

1019. the supply of broken stone.583 

338. Tresaguet’s pavement. 195 

975. water.568 

963. wing-walls. 564 

213, 216. wood-block pavements.124-132 

983. wrought-iron. 569 

985. interpretation of. 570 

986. omissions in. 570 

473. requirements for American natural cements. 254 

996. right to alter details in. 571 

334. variations in, for brick pavements. 193 

895. Speed of machine-brooms . 536 

404. steam-rollers. 216 

401. Spikes in steam-rollers, defects of. 215 

1033. number of, per mile of track. 614 

1033. size of. 614 

992. Spirituous liquors. 571 

1033. Splice-joints, number of, per mile. 614 

633. Spoil-banks. 338 

636. form of. 338 

383. Spreading the broken stone.209 

1036. Springfield steam-roller. 649 






















































760 


INDEX. 


.ARTICLE PAGE 

554. Springs on vehicles, effect of. 308 

'728. and retaining-walls.407 

"859. Sprinkling, amount of water required... 497 

-859. broken-stone pavements, amount of water required for. 497 

911. Sprinkling of streets. 442 

1036-1040. carts, capacity of.629, 668 

1036-1040. prices of.629, 668 

897. Squilgees for asphalt. 537 

prices of. 662 

888 . St. Louis, street-cleaning in ..534 

889. St. Paul, street-cleaning in. 534 

644-646. Stability of earth.341, 342 

451. pavements. 245 

637. Stakiug-out borrow-pits. 339 

933. bridges. 552 

931. culverts. 550 

929. curves. 550 

934. drains. 553 

930. side-slopes. 548 

936. street contours. 554 

938. structures. 555 

935. vertical curves. 553 

928. work. 550 

767. Statistics of streets for each of fifty of the largest cities in the 

United States (Table LXXXIII). 437 

Steam-drills, price of. 626 

402. -rollers, and grades.-.215 

404. area rolled per day.216 

403. cost of maintaining,. 215 

dimensions of.650 

405. manner of applying. 217 

415. picks on, objectionable. 220 

404. speed of. 216 

Steel, resistance to crushing of (Table XXIV). 77 

specific gravity of (Table XXIV). 77 

weight of (Table XXIV).• • • •. 77 

897. wire brooms. 587 

402. Steepest grade upon which a steam-roller can be operated. 215 

542. Steep grades, objections to. 303 

166. pavements on. . 91 

64. Stone, absorptive power of. 26 

412. amount of, worn away annually from broken-stone pave¬ 
ments. 220 

877. -block pavement, cost of cleaning.527 

load drawn by a horse on (Table LVII)... 302 

1038. tools used in the construction of. 653 

transverse rise for (Table LXIV).334 
















































INDEX. 


70*1 


ARTICLE PAGE 

159. Stone blocks, joint-filling for. 89 

601. ■ pavements, maximum grade for .327 

382. broken, quantity required per mile of different widths. 209 

355. coefficients of quality for broken-stone pavements (Table 

XXXVIII). 203 

369. crushers, capacity of. .. .206, 634 

■369, 370. cost of. . .206,634 

367. operating. 205 

370. horse power lequired for .206, 634 

367. price of.205, 634 

369. 370. size of.206, 634 

368. wear of.205 

370. weight of.206, 634 

371. crushing, cost of (Table XXX).206 

1036. forks, price of. 628 

151. gutters. 85 

1036. hammers, price of. 628 

133. pavements. 79 

152. paving-blocks at street-junctions. 85 

153. culling of.,. 53 

149. dressing of. 85 

361. quality of, for broken stone pavements. 201 

459. concrete. . 247 

371. quarrying, cost of (Table XXX). 206 

1036. rakes, price of . 628 

359. shape of, for broken-stone pavements. 204 

357. size of, for broken-stone pavements. 204 

438. size of, for trackways. 236 

437. trackways. 233 

366. Stones, breaking by hand. 205 

862. Storage and delivery of broken stone . 501 

Stourbridge fire-brick, specific gravity of (Table XXIV). 77 

resistance to (Table XXIV). 77 

crushing of (Table XXIV). 77 

weight of (Table XXIV). 77 

1036. Straight-edge, use of . 628 

225. Street-car rails and asphalt. 139 

31. tracks, city ownership of. 13 

868 . -cleansing. . 521 

898. carts and wagons...537 

893. cost of.536 

897. nand-brooms for.537 

oSl. in Ba lit more,. 531 

871. Berlin. 523 

882. Boston. 531 

883. Brooklyn. 533 

884. Cleveland. 533 

















































762 


INDEX. 


ARTICLE PAGE 

885. Street-cleansing in Detroit. 533 

880. London. 531 

886. New York. 533 

879. Paris. 530 

887. Philadelphia. 533 

888. St. Louis. 534 

889. St. Paul . 534 

890. Washington, D. C.534 

1027. specifications for. 586 

876. systems of. . 526 

899. dirt, disposal of. 537 

872. dust, composition of. 523 

749. grades. 420 

grades in various cities (Table LXXXII)..422 

751. intersections, arrangement of. 421 

766. carriageway at.. 436 

766. increasing width of. 436 

925. trees at. 548 

152. junctions, paving with stone blocks. 85 

763. lines and monuments . .. 481 

maintenance, annual cost per head of population in several 

cities of the United States (Table LXXXV1I). 528 

875. methods of cleansing.. 526 

872. mud, composition of (Table LXXXV),.524 

891. orderly system. 535 

878. patrol in Berlin. 503 

765. profiles. .. 434 

911. sprinkling. 542 

911. cost of. 542 

914. frequency of. 543 

913. quantity of water required. 543 

916. sea-water for. 544 

912. v systems of. 543 

767. Street statistics for each of fifty of the largest cities in the United 

States (Table LXXXIII). 437 

745. Streets, city.. 

57. excavations in. 23 

758. subfoundation, drainage of. 427 

759. surface-drainage of.. 

893. sweeping, cost of. 536 

756. transverse contour of.. 

752. grade of . 423 

917. trees on. 546 

910. washing. 54 ^ 

747. width of. 42 q 

in various cities (Table LXXXII). 422 

468. Strength compressive, of concrete . 251 
















































INDEX. 763 


ARTICLE PAGE 

473. Strength of cements. 254-270 

400-468. concrete. 248-251 

491,499. mortar. 265-270 

1045. Structures, annual cost of. 683 

938. setting stakes for. 555 

1012. Subletting contract. 577 

720. Substructure of bridges...399 

723. Surcharged walls. 402 

731. formula for. 407 

693. Surface-drainage. 375 

759. of streets. 428 

1033. -grader, price of. 610 

1033. use of.. 616 

•850. profit of improving the.491 

377. to find area of that which can be covered by a cubic yard 

of broken stone. 208 

1008. Suspend work, power to. 576 

1040. Sweepers, mechanical. 662-669 

858. Sweeping, time for.. 496 

893. streets, cost of. . 536 

66 . Syenite. 28 

875. Systems of street cleaning. 526 

856. maintenance. 494 

911. sprinkling. 442 

T 

797. Tar-concrete for footpaths. 462 

797 . footpaths, specifications for.462 

106. -gas. 62 

450<?. -macadam. 243 

88 a. -mineral. 39 

862. Team-labor and materials . 500 

422. Telford pavements, specifications for. 224 

342. Telford’s method of broken-stone pavements. 198 

344 . defects of.. 198 

483. Temperature, effect of variations on cement.260 

261. variation in, and aspluilt pavements...<. 152 

503. Tensile strength of mortar (Table XLVII). 272 

476. Portland cement. 257 

268. Test for bituminous rock.*. 163 

126. of the cleanness of sand. 75 

476. Testing cement, necessity of... 257 

492 . machine for cement.266 

60. Tests, breaking. 24 

973 . cement, specifications for. 567 













































764 INDEX. 


ARTICLE PAGE 

60. Tests, crushing. 24 

118. of brick.66 68, 69 

477. cement.. 258 

942. materials. 657 

61. Rattler. 25 

413. Thickness, loss of, on broken-stone pavements.220 

415. manner of restoring, on brokeu-stone pavements.220 

722. minimum, of retaining-walls. 402 

714. of abutments .... .393 

for arches (Table LXXVI).394 

713. arch. 390 

arch (Table LXXY). 392 

758. concrete. 247 

154. foundation. 88 

429. gravel layer...... 230 

378. the broken-stone pavement. 208 

384. layers of broken stone. 210 

958. Third-class masonry. 563 

689 Tile-drains. 373 

689. Tiles, diameter of. 373 

689. form of. 373 

689. lengthof. 373 

Timber bridges, dimensions for (Tables LXXIX and LXXX). 400 

980. specifications for.569 

858. Time for sweeping... 495 

1002. of completion. 574 

545. Tires, width of.305 

527. To find the force required to sustain a vehicle upon an inclined road. 300 

528. pressure of a vehicle against the surface of an inclined 

road—.300 

131. Tomkins Cove gravel. 76 

131. analyses of. 76 

1039. Tools employed for asphalt pavements. 654 

1038. block pavements. 653 

73. in the manufacture of granite paving-blocks. 30 

1040. for cleaning, price of. 662 

1037. for maintenance of broken-stone roads.500-653 

1033. grading. 605 

1032. grubbing, prices of. 604 

1036. macadamizing. 628 

1035. rock excavation. 622 

furnished by the administration. 500 

569. Topography. 311 

439. Trackways, cost of. 236 

438. in Italy . 236 

438. size of stone for. 236 

437. stone. 233 

















































INDEX. 


765 


ARTICLE PAGE 

597. Tractive force required in descending inclines.. 329 

force required to move a load of one ton on different pave¬ 
ments in Europe (Table LI). 298 

force required to move a load of one ton on different road- 
surfaces (Table L).295 

531. Tractive power and gradients. 300 

532, 533. of horses.300 

at different velocities (Table LIII). 301 

517, 520. Traction, resistance to (Table L).295-298 

45. Traffic census. 77 

393. defects of compacting the broken stone by the. 212 

228. sustained by asphalt. 140 

629. Transverse balancing. 337 

757. contour of streets.337 

936. staking out. 554 

618. roadways. 334 

625. on hillside roads. 336 

756. grade of streets.. 425 

467. strength of concrete. 251 

670. Transport of earth. 360 

5. Transportation-wagon, cost of. 2 

86. Trap-rocks. 36 

86. color of. 36 

87. resistance to crushing of (Table XIV). 37 

87. specific gravity of (Table XIV). 37 

87. weight of (Table XIV). 37 

923. Trees at street-intersections. 548 

924. distance apart to plant.548 

920. financial value of. 547 

919. on Belgian road. 546 

836. clay roads... 486 

917. roads. 545 

837. sand roads. 487 

917. * streets. 545 

918. the French roads. 546 

927. protection of. 549 

922. qualities of. 547 

922. selection of. 547 

927. specifications for protection of. 549 

917. use of..'. 545 

388. Tresaguet’s system of broken-stone pavements. 195 

100. Trinidad asphaltum.. 50 

100^. analyses of (Tables XIV a aud XV a) .42, 52 

100<?. preparation of. .. 52 

104. price of, in 1893. 51 

100. source of..."... 50 

740. Tunnels. 411 

Types of timber bridges. 398 


















































766 


INDEX. 


ARTICLE PAGE 

u 

607. Undulating grades. 329 

91a. Uiutailite. 40 

847. Unnecessary grades, profit of eliminating.489 

704. Use of catch-pools. 382 

124. sand. 74 

105. Uses of asphaltum... 62 

72. granite. 30 

9, 83. limestone. 4, 34 

464. Usual proportions for concrete. 249 

V 

Value of bluestoue used for street purposes in 1889 (Table XI)__ 34 

70. granite used for street purposes in 1889 (Table VII). 29 

842. improvements . 488 

limestone used for street purposes in 1889 (Table XIII).... 36 

sandstone used for street purposes in 1889 (Table X). 34 

334. Variations in specifications for brick pavements^. 193 

of temperature, effect of on asphalt pavements.137-152 

222, 261. cement. 260 

483. mortar. 260 

89. of asphaltum. 38 

120. Varieties of wood used for paving. 68 

543. Vehicles, character of. 30 

400. loaded pressure of. 214 

618. Vegetable soil, shrinkage of. 339 

630. Vertical curves. 331 

935. staking out. 553 

Vitrified pipe, weight of (Table LXXI). 387 

cost of (Table LXXI). 387 

461. Voids, determination of. 248 

372, 461. in broken stone. 206, 248 

353. to determine. 207 

372, 461. gravel. 206, 248 

127,462. sand...75’ 248 

280. Vulcanite pavement. 167 

881. Wages, in Baltimore. 531 

882. Boston. 531 

1043. Europe. 680 

879. Paris....,. 530 

73. of paving-block makers. 31 









































INDEX. 


ARTICLE 


rv n rv 
i O i 


PAGE 


w 


5. Wagon-transportation, cost of.2,681 

670. Wagons, dump. 360 

910. Washing, street. 542 

890. Washington, D. C., cleaning streets in.534 

56. Waste of money in opening pavements . 23 

484 Water, amount of, absorbed by cements (Table XLIV). 261 

484. required for mortars.261 

659. sprinkling, broken-stone pavements. 497 

695. breaks, objections to.377 

497. for mortar, quality of. 269 

224. injurious to asphalt. 138 

582. on mountain roads .321 

484. quantity of, for mortar.. 261 

363. required for concrete.249 

913. street-sprinkling.543 

specific gravity of (Table XXIV). 77 

975. specifications for.568 

weight of (Table XXIV). 77 

392. Watering broken-stone pavements. 212 

392. effect of excessive. . 212 

794. Wear of artificial stones. 456 

63. asphalt blocks. 26 

231. pavements.. 141 

63. brick. 26 

63, 409. broken-stone pavements.26, 219 

63, 168. granite pavements.26, 93 

63, 202. wood pavements.26, 92 

368. stone-crushers.205 

253. Wearing surface of Trinidad-asphalt pavements. 150 

729. Weep-holes... 407 

256. Weight of a cubic yard of asphalt paving-cement. 151 

470. American natural cement (Table XXIV). 77 

256. asphaltum (Table XXIV). 77 

basalt (Table XXIV). 77 

bitumen (Table XXIV). 77 

bituminous limestones (Table XXIV). 77 

bluestone (Table IX). 34 

brick (Table XXI). 68 

masonry (Table XXIV). 77 

374 . broken stone. 207 

cast iron (Table LXIV). 77 

480. cement. 259 


English Portland (Table XXIV) 














































768 


INDEX. 


ARTICLE 

707. Weight of cement pipe (Table LXYII). 

Roseudale (Table XXIV). 

chalk (Table XXIV). 

clay (Table XXIY).. 

with gravel (Table XXIY). 

common hard brick (Table XXIY).. 

457. concrete (Table XXIY). 

971. culvert-pipe (Tables LXXI, LXXYII). 

drain-tiles (Table LXXVII). 

earths (Table XXIY). 

feldspar (Table XXIV). 

flint (Table XXIY). 

French Portland cement (Table XXIV). 

glass (Table XXIY)... 

gneiss (Table XXIY)... 

69. granite (Table VI).. 

gravel with clay (Table XXIY). . 

gunpowder (Table XXIY).. 

1038. hand rammers.,. 

ice (Table XXIV). 

709. iron pipes (Table LXXIII). 

lead (Table XXIY). 

lime . 

84 limestone (Table XII)_'. 

liquid bitumen (Table XXIY). 

masonry (Table XXIY). 

mica (Table XXIV). 

mortar (Table XXIY). 

mud (Table XXIY). 

naphtha (Table XXIY). 

paving-bricks (Tables XXI, XXIa, XXIY) 

peat (Table XXIV). 

petroleum (Table XXIV). 

picks. 

pitch (Table XXIV). 

433. pit-gravel ... 

porphyry (Table XXIV). 

473. Portland cement (Table XXIV). 

pressed brick (Table XXIY). 

quartz (Table XXIV). 

rails.. . 

791. rammers for concrete... 

road-rollers... 

Roman cement (Table XXIV). 

Rosendale cement (Table XXIY). 

130. sand (Table XXIV) . 

81. sandstones (Table IX). 


PAGE 

.387 

. 77 

. 77 

. 77 

. 77 

. 77 

....77-247 
..387, 395 

. 395 

. 77 

. 77 

. 77 

. 77 

. 77 

. 77 

_ 28 

....77-231 

. 77 

. 654 

. 77 

. 388 

. 77 

. 77 

. 77 

. 77 

. 77 

. 77 

. 77 

. 77 

. 77 

68, 69, 77 

. 78 

.. 78 

. 605 

. 78 

. 231 

.. 78 

.. 77, 259 

. 77 

. 78 

.614 

..456 

. 646-650 

. 77 

.. 77 

... 75, 78 
. 33 


4 



















































INDEX. 769 


ARTICLE PAGE 

Weight of scrapers. 607-609 

serpentine (Table XXIV). 78 

shales (Table XXIV). 78 

shingle (Table XXIV). 78 

slate (Table XXIV). 78 

snow (Table XXIV). 78, 541 

soapstone (Table XXIV). 78 

soft inferior brick (Table XXIV)... 77 

steel (Table XXIV). 78 

1086. stone-crushers.. 684 

Stourbridge fire-brick (Table XXIV). 77 

87. trap-rocks (Table XXIV). 87 

water (Table XXIV). 78 

wood (Tables XXII, XXIV).73, 77 

wrought-irou (Table XXIV). 77 

707. vitrified pipe (Table LXXI). 387 

550. Wheels, advantages of..307 

410. effect of, on pavements. 220, 308 

518. power required to draw, over obstacles. 289 

520. rolling resistance of.294 

549. size of. 307 

1038. Wheelbarrows. 610 

327. Wheeling, plan of brick pavements. 186 

613. Wheelway, minimum width of. 324 

611. Wide roads . 324 

747. Width of carriageway, increasing of, at street-intersections. 420 

747. city streets. 420 

769. footpaths........ . 438 

191. joints in wood pavements. 114 

616. land appropriated iii various localities for roads....324 

617. mountain roads...<. 325 

147. paving-blocks. 84 

611. roads. 324 

587. roadways on curves . 324 

sidewalks in various cities (Table LXXXII).422 

streets in various cities (Table LXXXII).422 

545. tires. ••• 305 

548. tires in Austria. 306 

547. Bavaria. 306 

546. Width of tires in France. 306 

963. Wing walls, specifications for. 564 

742. Wire fence, cost of . 412 

1036. Wire screens, price of. 653 

120. Wood. 68 

63. abrasion of. 26 

64, 422. absorptive power of (Table XXIII).26, 74 

450. and iron, combination of.. 241 




















































770 


INDEX. 


ARTICLE 

183. wood blocks,, number per square yard 


188. chemical treatment of.* 

122. creosoting, advantage of. 

188. cost of........ 

748. for footpaths... 

177. pavements, advantages of. 

874. amount of dirt produced by, 

181. and death rate. 

186. chief cause of the failure of 


PAGE 

. 109 

. Ill 

. 74 

. 112 

.440 

.104 

.526 

. 107 

. 110 


l 


877. 

205. 

206. 

27, 193. 
184, 

385 .’]” 

27.. 

214. 

599. 

179., 

19., . .. 
213, 216, 


182.. , 

63, 202, 

190. 

182. 

181. .... 
189. ... 
192. 

187. 

191. 

188. 


cost of cleaning. 527 

cost of construction (Table XXXIII). 119 

maintenance. * 120 

durability of.....,.11, 115 

essentials necessary to successful construction.... 110 

foundations used for. 110 

life.of. . .* 11 

maintenance by contract.128 

maximum grade for... J. 327 

objections to. 105 

,. slipperiness of,,. 9 

.specifications for. 124-132 

transverse, rise for (Table LXIY). 334 

variety of systems. 109 

wear of.. ,.26, 118 

paving blocks, expansion of...... 114 

shape of. 109 

size of..,,... 109 

dimensions of blocks for. 113 

filling for joints.*. 114 

quality of the wood. Ill 

width of joints........ 114 

preservation of......... Ill 


121. .... quality, of, for paving... 

resistance to crushing of (Table XXII). 

specific gravity of (Table XXII). 

120. varieties used for paving... 

.weight of (Table XXII)... . ..... . ... 

719. Wooden bridges-• .. .... 

.dimensions, of (Tables LXXIX and LXXX),. 


736. railings for.road protection.... 

188. Woods best adapted to chemical treatment. 

1001. Work, commencement of... 

998. . defective.,,,.. . . 

534. done. by horses. 

1007. ...... faithful performance of, bond for... 

999. how measured,. ..... 

1010..miscellaneous..... 


.]: 73 

.. 73 

. 73 

. 68 

. . 73 

.. 397 

..... 398 
..... 409 

. 113 

.574 

.572 

.301 

....,; 576 
..... 572 
..... 576 
















































































INDEX. 


rvrv i 

( I L 


ARTICLE PAGE 

1008. Work, power to suspend. 576 

1003. progress of. 574 

1013. Workmen, payment of. 577 

983. Wrought-iron, specifications for. 569 

91. Wurtzilite. 40 

Z 

680. Zero-point, to ascertain, by calculation. 370 

591. Zigzags, objections to. 323 










' 



/ - ' 


* . 






. 




$ ' 


■ 










































INDEX TO ADVERTISEMENTS. 

PAGE 

. American Road Machine Company. 18 

Ames Plow Company. 17 

Anchor Post Company, The. 12 

Austin Manufacturing Company, F. C. 2 

Barber Asphalt Paving Company, The. 9 

Berlin Iron Bridge Company, The. 19 

Buffalo Fence Wire Company. 15 

Carlin’s Sons, Thomas. 13 

Carpenter Brothers. 14 

Chapman Manufacturing Company, The. 7 

Cockburn Barrow and Machine Company, The. 6 

Enterprise Manufacturing Company. 16 

Gates ilron Works... n 

Harrisburg Foundry and Machine Works. 17 

Hoyt & Sons, Stephen. 20 

Kelly Company, The O. S. 12 

McDonald & Son, H. W. 20 

New York & Bermudez Company. 4 

Pierce & Miller Engineering Company. 5 

Pioneer Iron Works. 7 

Pitts Agricultural Works, The. 12 

Pope Reversible Street Roller Company. 10 

Rand Drill Company. 1 

Rendrock Powder Company. 1 

Stone Road Construction Company, The. 8 

Sweeney & Son, E. 18 

Wiley & Sons, John. 20 

Wilson & Baillie Manufacturing Company, The. 3, 
































- •< 




N ■ 




































' 

























































AVOID ACCIDENTS ! 

PREVENT LAW SUITS !! 

SAVE MONEY ! !! 

Contractors working in the City Limits should use 


RACKAROCK. 

tttw—THT" p—— • "■ ■ " --■!— ■TMm-rnnrraTMM-^ • — mi r \i iiBirnniwnan— i 

STRONGER THAN No. I DYNAMITE. Perfectly Safe In Using, Handling, and Storing. 

WILL MOVE THE ROCK OR SHATTER IT, 

According to manner of using it. 


BLASTING BATTERIES, FUSES, CAPS, Etc. 

RENDROCK POWDER CO., 

23 Park Place, New York. 

RAND’S 

LITTLE GIANT O H P 1/ H t? 1 I I ^ 

AND SLUGGER i\v^v>rv Ur\ILLj) 

For Sewers, Cellars, Streets, Mines, Quarries, Etc. 

AIR COMPRESSORS, 

BOILERS MOUNTED ON WHEELS. 

Hose, Steel, Pipe, Wire Rope, Etc. 

SEE ILLUSTRATION, PAGE 353. 

RAND DRILL CO., 

23 PARK PLACE, NEW YORK. 










ROAD TOOLS. 

Each of these Machines was Awarded the HIGHEST MEDAL 
in its Class at the WORLD’S FAIR. 



^HE jaws having a compound oscillating 
movement, the crushing of rock is con¬ 
tinuous, the upper and lower half of the jaws 
crushing alternately. 

Our crusher embodies an entirely new prin¬ 
ciple whereby weight is reduced, capacity in¬ 
creased, less power required and life of Crush¬ 
er prolonged. We claim, all things considered, 
to have the best Crusher made, and court 
comparison. Capacity up to 250 tons per day. 


AUSTIN ROCK=CRUSHER. 



AUSTIN STEEL REVERSIBLE ROAD 
MACHINE. 


The strongest, neatest, and most complete Grader 
sold. Saves 75 per cent in cost of work over old 
methods. Energetic agents wanted in unoccupied 
territory. 



AUSTIN REVERSIBLE ROLLER. 


Has anti-friction roller bearings. No weight on 
horses’ necks. Is reversed or brake applied by 
driver without leaving his seat. Lightest draft 
and most easily handled. 1 £, 3*, 4, 5, 6, and 7 tons 



AUSTIN STEEL STREET=SWEEPER. 


Lightest running, strongest and most efficient. 
Two horses only. Sweeps 7} ft. Cleans thor¬ 
oughly any kind of pavement. 



AUSTIN DUMP*WAGON. 


Quickly and easily dumped without stopping the 
horses. Has steel pan and steel-lined box. Holds 
1} to 2 yards. Used for hauling earth, brick, sand, 
stone, coal, street-sweepings, etc. 


ALSO SPRINKLERS. 


For Catalogue and Particulars address 
















































“KOSMOCRETE” SIDEWALKS, 4c. 

We Refer to 3,450,000 Square Feet of “ KOSMOCRETE ” 
(Portland Cement) ARTIFICIAL STONE WORK, 

Constructed under a Guarantee of FIVE YEARS, 
Comprising Sidewalks, Garden Paths, Driveways, Curbs, Copings, Steps, 

Reservoir Walls, 
Railroad Station 
Platforms, Cellar 
Floors, Watertight 
and Fireproof 
Warehouse and 
Stable Floors, &c. 


Contractors for 

HEAVY ' 
CONCRETE 
CONSTRUCTION. 

THE WILSON & BAILLIE M’F’G CO., 

__ 85 to 93 Ninth Street, BROOKLYN, N. Y. 

“KOSMOCRETE” SEWER PIPEJ-a 

NEW PATENT 

MACHINE-MADE 

(PORTLAND CEMENT) 

Sewer i Culvert Pipe 

“Egg-Shape and Round, 
with Flat Rase.” 

WELL. PIPE 

AND 

CHIMNEY FLUES. 

Consulting and Constructing 
Engineers are invited to call and 
examine this wonderful Machine 
and its products. 

Our new patent machine-made 
Pipe are positively the strongest 
and the most desirable shape 
Pipe in the market. 

THE WILSON & BAILLIE M’F’G CO., 

85 to 93 Ninth Street, BROOKLYN, M. Y. 















































































































































































































/ 



THE NEW YORK and 

BERMUDEZ CO. 


3 YU A o >1 b rn sldBJgujbA 

having acquired by purchase the largest lake or deposit of Asphalt in the 
world, covering an area of over 1,000 acres, situated in the State of Bermudez, 
Venezuela, and having expended large sums of money in perfecting ship¬ 
ping facilities, are now prepared to sell and deliver a refined Asphalt of 
over 95 per cent, purity and of a quality far superior to any other for 
paving, roofing, etc. It will do 50 per cent, more work than any other 
Asphalt. We guarantee its excellence and purity, and Prof. E. J. DeSmedt, 
our chemist, will give scientific and expert instructions to parties using it= 


HEW YORK & BERMUDEZ COMPANY, 

25 BEAVER STREET, 

NEW YORK. 


4 









/ 


“Brennan” Rock Crusher 

* 

MAKES 

PERFECT MACADAM MATERIAL. 



It CUBES the Stone. Product UNIFORM 
Size. Adjustable to make ANY Size 
Without Stopping. SMALL Sizes 
MOUNTED on WHEELS 
if Desired. 


ENGINES AND BOILERS, 

MOUNTED AND STATIONARY. 

SCREENS, CONVEYERS, 

COMPLETE PLANTS FURNISHED. 


PIERCE & MILLER ENGINEERING CO., 

49 CORTLANDT STREET, 

NEW YORK CITY. 

5 


( 

y 

















































New Concrete Mixing Machines. 



Coal and Ash Buckets. 

Lasher’s Piston Springs. 

Heavy and Light Forgings. 
Patent Tubular Frame Wheelbarrows. 
Coaling Tubs. 

r ✓ 

' Coal and Coke Cars. 

* 

Jones’ Piston Springs. 

Furnace Charging Barrows and Cars. 

- * ■* 

The Cockburn 
Barrow and Machine Co. 

i • ■ 

Sheet Iron Work of Every Description. 
Roofers’ Tar Boiling Kettles. 

Every Description of General Forgings. 
Patent Power Punching Machines. 

Patent Eureka Steam Hammers. 
Dimpfel Blowers. Machine Work. 


OFFICE AND WORKS, 

234 to 240 ELEVENTH STREET, 
JERSEY CITY, N. J. 

1 y 

New Concrete Mixing Machines. 

See pages 606 and 607. 












See pages 6 1 O and 6 1 5, body of book. 


THE 


* * * 


CHAPMAN MFQ. CO. 

Formerly the Chapman-O’Neill Mfg. Co. 

Sole Proprietors ov I Manufacturers of 

the: Machine and Push Brooms 

FOR ALL PURPOSES 


“Pride of New York” 

O ’NEIL’S 

Standard Street 

Sweeping Machines, 


AND DEALERS IN 


Contractor’s and Rail= 
way Supplies. 


Macli inists, Wheelwrights, 
and 

General Blacksmiths. 


OFFICE AND WORKS: 

508 & 5 1 O EAST 1 9th STREET, NEW YORK. 

CATALOGUE WILL BE MAILED UPON A/’PLICATION. 


“PIONEER” Steam Road Roller. 



For making Macadamized and Asphalt Roads. 

HIGHEST RECOMMENDATIONS FROM PARTIES HAVING THEM IN USE. 

IS ALSO A GOOD LAWN ROLLER. 

address PIONEER IRON WORKS, Brooklyn, N. Y. 

7 































































































































THE STONE ROAD CONSTRUCTION COMPANY, 

of Bridgeport, Conn., is fnlly equipped with the 
tools and machinery employed in the modern 
construction of Highways. It is managed by 
practical men, who have been identified with the 
construction of what are acknowledged to be the 

4 

loest examples of road construction in the country. 
Their plant, comprising Bock-Drills, Rock-Crushers, 
Wheeled Scrapers, Dump-Carts, Rammers, Graders, 
Levellers, Concrete Mixers and Steam Road-Rollers, 
is probably the equal of any. 

The Company solicits correspondence in re¬ 
lation to road construction and drainage through¬ 
out the New England and Middle States. 

THE STONE ROAD CONSTRUCTION CO. 

OFFICE: 7 WALL ST., BRIDGEPORT, CONN. 

President,.E. W. DEWHIRST. 

Secretary and Treasurer, - C. E. WILLIAMS. 

Superintendent, - W. E. PARKER. 

8 









THE BARBER ASPHALT PAYING CO. 



IMPORTERS AND REFINERS OF 

TRINIDAD LAKE ASPHALT 


AND CONTRACTORS FOR 

TRINIDAD LAKE ASPHALT PAVEMENTS 


17 , 000,000 


Square Yards of TRINIDAD ASPHALT 
PAVEMENT Laid in the United States, 

OF WHICH 


8 , 000,000 


Square Yards, or over 500 MILES, have 
been Laid by this Company during- the 
past Seventeen Years, 


IN THE CITIES OF 


Washington, Philadelphia. Baltimore, New York, Long Island City, 
Jersey City, Yonkers, Mt. Vernon, Newark, Long Branch, Newport, 
Cambridge, Boston, Albany, Schenectady, Niagara Falls, Buffalo, 
Scranton, Wilkesbarre, Reading, Harrisburg, Altoona, Erie, 
Youngstown, Ft. Wayne, Chicago, Cicero, Omaha, St. 

Joseph, Topeka, Kansas City, Wyandotte, Westport, 

Wichita, St. Louis, Louisville, and New Orleans. 


Wherever this Pavement has been introduced it has come to stay, and has never been 
taken up or replaced by another form of Pavement. It is the 

STANDARD PAVEMENT OF AMERICA 


F. V. Green, President, J. C. Rock, Secretary. 

C. K. Robinson, Treasurer. F. J. Bristol, Assistant Secretary. 

P. W. Henry, Ass’t to the President. 


Principal Offices: 

LE DROIT BUILDING, WASHINGTON, D. C. 

WASHINGTON BUILDING, No. 1 BROADWAY, NEW YORK. 

9 



































POPE REVERSIBLE STREET ROLLER CO. 

MORE THAN 200 ROLLERS NOW IN USE. . 


Having built more streets and roads for less cost throughout the West and 
South than all the other rollers added together. 

Overcoming All Objections to Steam Rollers for 90 Per Cent. Less Cost. 



The discovered diameter overcom¬ 
ing’ the push. 

The only means we have to com¬ 
pact under the i oiler and discover 
soft places as intended. 

Co ing abreast on one shaft with 
the required diameter produces the 
best results with less weight of roller. 

No stalling in soft places. 

No frightening of teams on public 
highways, 

No repairs for seven years wanted. 


BUILD 

4, 5, 6 

AND 

7-TON 

Rollers. 


ROLLER CONTROLLED BY ONE SHAFT. 
REVERSIBLE TONGUE. 

PROPORTIONAL DIAMETER. 
ANTIFRICTION ROLLER BEARINGS. 


Commands equal action and better results than Steam Rollers, for less cost, 
and explodes the old theory that heavy rollers produce the bes tresults. It’s 
in the diameter of roller to carry the weight ; for less stone in thin layers, and 
more rolling, will produce best results for less cost. 

Patented April 8th, 1 8S4, and June 27th, 1 893. 

All other makers of this Roller are infringers and the users are 
equally responsible with the unlicensed manufacturer. Send for catalogue 
list of sales and endorsements. 

This Roller won on its merits: World’s Fair Supreme Award of 
Medal, Diploma, and Diploma of Honorable Mention. 


POPE REVERSIBLE STREET ROLLER COMPANY, 

GENERAL OFFICE: 

S O <5 Cha m ber of Co m m erce Building, 
CHICAGO, ILL., IT. S. A. 

to 








Oates’ Rock Ore Breaker, 


The Most Valuable Machine in the World for Improving 
Highways. It has Worked a Complete Revolution 
in Stone Breaking. Over 3,000 in use. 



MADE EITHER STATIONARY OR PORTABLE. 


We have Designed and Bu ilt t he Largest Macad&m and 
Ballast Plants;, Screens, Elevators, Cars, Steam Plants, 


GATES IRON WORKS, 


BRANCH OFFICE AT 

136 LIBERTY ST., N. Y. 


50 S. Clinton St., CHICAGO. 



























































































































































































































TH E ANCHOR POST CO. 



MANUFACTURERS OF A 'LL KINDS OF 

IRON & WIRE FENCES, ENTRANCE GATES, 
RAILINGS, POULTRY, TENNIS COURTS, 
AND DOG KENNEL ENCLOSURES. 

WRITE FOR CATALOGUE. 






.-c.. ■ ‘ 

LAWN TENNIS S POULTRY FENCES, 


LAWN FENCE. 



Sections . of .p osts . 


ENTRANCE gates of every description./ 



DRIVING THE POSTj 


We make a specialty of all kinds of fences for country places, farms and 
parks, and for this purpose offer a greater variety of styles and designs than any 
other firm in the country. 

Write for illustrated catalogue giving full description and prices of all our 
fences. Estimates also given on fences made to order for special purposes. 

i 

Office: No. 3 Seymour Building - , East 42 d Street, NewVork. N. Y. 



Handsome illustrated catalogue sent free on annlication. 


Buffalo flMtts 2>ouble Engine Steam IRoah IRolleis 

'THE ABOVE ROLLER is the 
1 only one purchased by the United 
States Government in competition 
with all other machines, and after 
the most rigid practical tests and 
critical examinations made by th* 
Expert Engineer of the War Depart¬ 
ment. For information, catalogues, 
prices, etc., address 

THE PITTS AGRICULTURAL WORKS, 

15 Court Square, Boston, Mass. BUFFALO, N. Y. 7.6 Park Place, N. Y. City. 

12 





















































































































































































































We Manufacture Contractors’ Machinery. 

HOISTING ENGINES, 

Derricks and Pile Drivers, 

HOISTING TUBS, 

WIRE ROPE, 

DUMP CARS, ROAD ROLLERS, CONCRETE MIXERS, 

Engines, Boilers, and Pumps, 

SEWER INLETS, 

All Iron, or for Brick Setting. 

PARK INLETS, 

MANHOLES, 

GUTTER CROSSINGS, Etc. 

GRINDING AND MIXING MACHINERY, AND BRICK-YARD SUPPLIES. 
THOMAS CARLIN’S SONS. 

ALLEGHENY, PA, 

STANDARD WORKS 

FOR 

Civil engin 


Baker’s Masonry Construction. 

Sixth edition. 8vo, cloth, ...... $5.00 

Johnson’s Theory and Practice of Surveying 1 . 

Eleventh edition. 8vo, cloth, . . . . . 4.00 

Wellington's Railway Location. 

Fifth edition. 8vo, cloth, . . . . . . 5.00 

Searles’ Field Engineering 1 . 

Sixteenth edition. 12mo, morocco, .... 3.00 

Trautwine’s Civil Engineer's Pocket Book. 

Sixteenth edition. 41st thousand. 12mo, morocco, . 5 00 

Mahan’s Civil Engineering 1 . 

Revised by DeVolson Wood. 8vo, cloth, . . . 5.00 

Wheeler’s Civil Engineering 1 . 

Fourth edition. 8vo, cloth, . . . . . . 4.00 


JOHN WILEY & SONS. 

53 East Tenth Street, NEW YORK. 


EERS. 






13 
















ESTABLISHED 1872. 



STONE DELIVERED BY THE CARGO. 



DEALERS IN 


MACHINE CRUSHED 
TRAP ROCK. 

PALISADE QUARRIES 

At FORT LEE, N, J. 


iVIairr Office at l J or Leicester, N. Y. 


We are now prepared to furnish Crushed Trap 
Rock, in uniform sizes, free from dust, for Con¬ 
cretes, Macadam purposes, and Ballast. 

The superiority of Trap Rock for these pur¬ 
poses is conceded, and our location at the lower end 
of the Palisades, in New York Harbor, with our 
unequalled plant, consisting' of two of the largest 
Brennan Breakers, two large Gates Breakers, and 
three large Ansonia Breakers, making our daily 
capacity (when all the machines are running) 750 
cubic yards, enables us to deliver stone with un¬ 
usual promptness. 

We have the largest Trap Rock Plant on the 
river, and the best facilities for loading vessels. 

Trap Rock delivered by scow load at any point 
on Tide Water or Canals. 

Trap Rock Stone for Telford Pavements. 

Hoping to have an opportunity to bid on any 
requisition you may make for this material, we are 

Very truly yours, 

CARPENTER BROTHERS, 

PORTCHESTER, NEW YORK, 
14 


















HATHAWAY FEHCE WIRE 


Pat. Hoy. 19,1889. 



Above Cut is One-half Actual Size of Regular Wire. 


This wire is made of best quality galvanized steel 
wire, and is made in two widths, the “ Regular” 
being If inches and the “ Wide " 34 inches in width. 
There is a growing prejudice against the use of 
barbed wires, and we believe 

THE HATHAWAY 

IS THE BEST BARBLESS FENCE WIRE MADE. 

It is strong, durable* handsome, is not affected by 
cold or heat, and from the increasing demand is 
evidently growing in favor. It has been adopted as 
the standard fencing by some of the leading rail¬ 
ways, and is in use on many of the largest stock 
farms in the country. 

On account of the width of strand it is easily seen 
by stock, and it is impossible for them to be injured 
by it as with barbed wire. 

MANUFACTURED BY 
* 

BUFFALO FENCE WIRE CO., 

317-32 1 Washington Street, 

BUFFALO, N. Y. 


15 












































































































































































































/ 


THE 



AMES PLOW COMPANY, 

OF BOSTON AND NEW YORK, 

| j EREBY solicits your trade for Grading 
and Hard Pan Plows, Two-wheel and 
Four-wheel Dump Carts, Wagons, Drag and Wheel-Scrapers, 
Wheelbarrows, Picks, Shovels, Mattocks, Paving Rammers, etc. 
They manufacture the Truss Beam Hard Pan Plow illustrated 

on page 606; also the Corrugated Sectional Roller and Sprink. 

✓ 

ling Cart on page. 629. And they carry in stock a full line of 
K. & J. Col umbus Scrapers, Barrows, etc., as shown on pages 

607 to 610. 



Ames 

Shovels 

and 

Picks 

Are the 

Best. 


WRITE FOR PRICES AND 
MENTION THIS PUBLICA¬ 
TION.. . . . 



Quick 


Pointers 


>jphis Machine is used 
by more than ioo 
leading cities in the 
United States. 




Is It -wisdom to use a STEAM ROAD.ROLLER 


oi the best mechanical design and construction § 


17 






























CHAMPION ROAD TOOLS 

ARE FIRST IN QUALITY AND BEST IN RESULTS, 

If you buy a Champion Rock=Crusher, Road=Roller, or 
Road Machine you have the satisfaction of knowing you have 
the best machine of its class made. 


WRITE FOR OUR CATALOGUE; 
IT IS FREE AND WILL 
INTEREST YOU. 



The Champion Portable Steel Rock-Crusher, 
, built in three sizes, from seven to thirty tons 
The Champion Distributing Cart spreads per hour capacity. Complete plants 
stone evenly to any desired depth. equipped 

AMERICAN ROAD MACHINE CO., 

Kennett Square, Pa, 


E. SWEENEY. 


JAMES J. SWEENEY. 


E. SWEENEY & SON 


WHOLESALE DEALERS IN 


North River Bluestone. 


GENERAL OFFICE: 

229 BROADWAY, NEW YORK. 

Opposite General Post Office. 

TELEPHONE CALL, 2418 B, CORTLANDT. 

DEPOTS: 

WILBUR, Ulster County, New York. 

SAUQERTIES, Ulster County, New York. 

18 













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19 




































































































































































STAR SEWER AND ROAD INLETS. 

MANUFACTURED BY 

H. W. McDonald & Son, - - Galion, 0. 

These Inlets, calculated for conducting surface-water into sewers and 
under-drains, are made with straight fronts or of any desired radius , and can 
be used as catch-basin covers or connected with sewer-pipe of any preferred 
diameter. 

25 DIFFERENT PATTERNS, 

EACH WITH REMOVABLE WROUGHT-IRON GRATES AND 
INTERLOCKING MANHOLE-LIDS. 

Neat, Strong, Durable, and Guaranteed to Render Satisfaction. 

City, county, and town officials will find it to their interest to corre¬ 
spond with us before preparing plans and specifications for street and road 
improvements. 

Send for Illustrated Catalogue and Price List. (Seepages 6 77, 678.) 


The New Canaan Nurseries. 


OVER 300 ACRES IN TREES, SHRUBS, ETC. 


STREET AND PARK TREES A SPECIALTY. 


\ \ 7E have the largest stock* of Maples, Tulip, Linden, Ash, Beech, 
’ * Birch, Poplars. Oaks, Willows, etc., this side of Rochester, if not 
the largest in this country. We also have acres and acres of Fruit Trees, 
Currants, Raspberries, Blackberries, and other fine fruits. Shrubbery, 
Roses, Evergreens, Hedging, Asparagus, and in fact everything necessary 
to fit up a large place, parks, roads, etc. This stock is grown upon our 
home land and is well adapted to the soils and climate of New England 
and vicinity. We can fill large or small orders and will guarantee satis¬ 
faction to customers. Personal inspection of our stock is earnestly 
requested. 

Send for Catalogue. Address 

STEPHEN HOYT’S SONS, 

NEW CANAAN, CONN. 

Nurseries 44 miles from New York City via Siamford Branch from Stamford. 


Books on Roads and Pavements 

PUBLISHED BY 

JOHN WILEY & SONS, 

53 East Tenth Street, = = New York. 


A TEXT-BOOK ON ROADS AND PAVEMENTS. By Fred. P. Spalding, Assistant 
Professor of Civil Engineering in Cornell University. 12010, cloth, $2.00. 

ROADS AND PAVEMENTS IN FRANCE By Alfred Perkins Rockwell, A.M., Ph.B., 
formerly Profess >r of Mining in the Sheffield Scientific School and at Massachusetts 
Institute of Technology. i2ino, cloth, $1.25. 















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